@article {69154, title = {Failure to mate enhances investment in behaviors that may promote mating reward and impairs the ability to cope with stressors via a subpopulation of Neuropeptide F receptor neurons.}, journal = {PLoS Genetics}, volume = {20}, year = {2024}, month = {2024 Jan 18}, pages = {e1011054}, abstract = {

Living in dynamic environments such as the social domain, where interaction with others determines the reproductive success of individuals, requires the ability to recognize opportunities to obtain natural rewards and cope with challenges that are associated with achieving them. As such, actions that promote survival and reproduction are reinforced by the brain reward system, whereas coping with the challenges associated with obtaining these rewards is mediated by stress-response pathways, the activation of which can impair health and shorten lifespan. While much research has been devoted to understanding mechanisms underlying the way by which natural rewards are processed by the reward system, less attention has been given to the consequences of failure to obtain a desirable reward. As a model system to study the impact of failure to obtain a natural reward, we used the well-established courtship suppression paradigm in Drosophila melanogaster as means to induce repeated failures to obtain sexual reward in male flies. We discovered that beyond the known reduction in courtship actions caused by interaction with non-receptive females, repeated failures to mate induce a stress response characterized by persistent motivation to obtain the sexual reward, reduced male-male social interaction, and enhanced aggression. This frustrative-like state caused by the conflict between high motivation to obtain sexual reward and the inability to fulfill their mating drive impairs the capacity of rejected males to tolerate stressors such as starvation and oxidative stress. We further show that sensitivity to starvation and enhanced social arousal is mediated by the disinhibition of a small population of neurons that express receptors for the fly homologue of neuropeptide Y. Our findings demonstrate for the first time the existence of social stress in flies and offers a framework to study mechanisms underlying the crosstalk between reward, stress, and reproduction in a simple nervous system that is highly amenable to genetic manipulation.

}, keywords = {Animals, Drosophila melanogaster, Female, Humans, Male, Neurons, Neuropeptides, Reproduction, Reward, Sexual Behavior, Animal}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1011054}, author = {Ryvkin, Julia and Omesi, Liora and Kim, Yong-Kyu and Levi, Mali and Pozeilov, Hadar and Barak-Buchris, Lital and Agranovich, Bella and Abramovich, Ifat and Gottlieb, Eyal and Jacob, Avi and N{\"a}ssel, Dick R and Heberlein, Ulrike and Shohat-Ophir, Galit} } @article {65311, title = {Behavioral features of motivated response to alcohol in Drosophila.}, journal = {bioRxiv}, year = {2020}, month = {2020 Feb 17}, abstract = {

Animals avoid predators and find the best food and mates by learning from the consequences of their behavior. However, reinforcers are not always uniquely appetitive or aversive but can have complex properties. Most intoxicating substances fall within this category; provoking aversive sensory and physiological reactions while simultaneously inducing overwhelming appetitive properties. Here we describe the subtle behavioral features associated with continued seeking for alcohol despite aversive consequences. We developed an automated runway apparatus to measure how Drosophila respond to consecutive exposures of a volatilized substance. Behavior within this Behavioral Expression of Ethanol Reinforcement Runway (BEER Run) demonstrated a defined shift from aversive to appetitive responses to volatilized ethanol. Behavioral metrics attained by combining computer vision and machine learning methods, reveal that a subset of 9 classified behaviors and component behavioral features associate with this shift. We propose this combination of 9 be

}, author = {Catalano, Jamie L. and Mei, Nicholas and Azanchi, Reza and Song, Sophia and Blackwater, Tyler and Heberlein, Ulrike and Kaun, Karla R.} } @article {65870, title = {Social hierarchy is established and maintained with distinct acts of aggression in male Drosophila melanogaster.}, journal = {Journal of Experimental Biology}, year = {2020}, month = {2020 Dec 02}, abstract = {

Social interactions pivot on an animal{\textquoteright}s experiences, internal states, and feedback from others. This complexity drives the need for precise descriptions of behavior to dissect the fine detail of its genetic and neural circuit bases. In laboratory assays, male reliably exhibit aggression, and its extent is generally measured by scoring lunges, a feature of aggression in which one male quickly thrusts onto his opponent. Here, we introduce an explicit approach to identify both the onset and reversals in hierarchical status between opponents and observe that distinct aggressive acts reproducibly precede, concur, or follow the establishment of dominance. We find that lunges are insufficient for establishing dominance. Rather, lunges appear to reflect the dominant state of a male and help in maintaining his social status. Lastly, we characterize the recurring and escalating structure of aggression that emerges through subsequent reversals in dominance. Collectively, this work provides a framework for studying the complexity of agonistic interactions in male flies enabling its neurogenetic basis to be understood with precision.

}, issn = {1477-9145}, doi = {10.1242/jeb.232439}, author = {Simon, Jasper C and Heberlein, Ulrike} } @article {64875, title = {Enabling cell-type-specific behavioral epigenetics in Drosophila: a modified high-yield INTACT method reveals the impact of social environment on the epigenetic landscape in dopaminergic neurons.}, journal = {BMC Biology}, volume = {17}, year = {2019}, month = {2019 Apr 10}, pages = {30}, abstract = {

BACKGROUND: Epigenetic mechanisms play fundamental roles in brain function and behavior and stressors such as social isolation can alter animal behavior via epigenetic mechanisms. However, due to cellular heterogeneity, identifying cell-type-specific epigenetic changes in the brain is challenging. Here, we report the first use of a modified isolation of nuclei tagged in specific cell type (INTACT) method in behavioral epigenetics of Drosophila melanogaster, a method we call mini-INTACT.

RESULTS: Using ChIP-seq on mini-INTACT purified dopaminergic nuclei, we identified epigenetic signatures in socially isolated and socially enriched Drosophila males. Social experience altered the epigenetic landscape in clusters of genes involved in transcription and neural function. Some of these alterations could be predicted by expression changes of four transcription factors and the prevalence of their binding sites in several clusters. These transcription factors were previously identified as activity-regulated genes, and their knockdown in dopaminergic neurons reduced the effects of social experience on sleep.

CONCLUSIONS: Our work enables the use of Drosophila as a model for cell-type-specific behavioral epigenetics and establishes that social environment shifts the epigenetic landscape in dopaminergic neurons. Four activity-related transcription factors are required in dopaminergic neurons for the effects of social environment on sleep.

}, issn = {1741-7007}, doi = {10.1186/s12915-019-0646-4}, author = {Agrawal, Pavan and Chung, Phuong and Heberlein, Ulrike and Kent, Clement} } @article {64917, title = {A neural circuit encoding the experience of copulation in female Drosophila.}, journal = {Neuron}, volume = {102}, year = {2019}, month = {2019 Apr 26}, pages = {1025}, abstract = {

Female behavior changes profoundly after mating. In Drosophila, the mechanisms underlying the long-term changes led by seminal products have been extensively studied. However, the effect of the sensory component of copulation on the female{\textquoteright}s internal state and behavior remains elusive. We pursued this question by dissociating the effect of coital sensory inputs from those of male ejaculate. We found that the sensory inputs of copulation cause a reduction of post-coital receptivity in females, referred to as the "copulation effect." We identified three layers of a neural circuit underlying this phenomenon. Abdominal neurons expressing the mechanosensory channel Piezo convey the signal of copulation to female-specific ascending neurons, LSANs, in the ventral nerve cord. LSANs relay this information to neurons expressing myoinhibitory peptides in the brain. We hereby provide a\ neural mechanism by which the experience of\ copulation facilitates females encoding their mating\ status, thus adjusting behavior to optimize reproduction.

}, issn = {1097-4199}, doi = {10.1016/j.neuron.2019.04.009}, author = {Shao, Lisha and Chung, Phuong and Wong, Allan and Siwanowicz, Igor and Kent, Clement F and Long, Xi and Heberlein, Ulrike} } @article {49013, title = {Repetitive aggressive encounters generate a long-lasting internal state in Drosophila melanogaster males.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, year = {2018}, month = {2018 Jan 16}, pages = {1099-104}, abstract = {

Multiple studies have investigated the mechanisms of aggressive behavior in Drosophila; however, little is known about the effects of chronic fighting experience. Here, we investigated if repeated fighting encounters would induce an internal state that could affect the expression of subsequent behavior. We trained wild-type males to become winners or losers by repeatedly pairing them with hypoaggressive or hyperaggressive opponents, respectively. As described previously, we observed that chronic losers tend to lose subsequent fights, while chronic winners tend to win them. Olfactory conditioning experiments showed that winning is perceived as rewarding, while losing is perceived as aversive. Moreover, the effect of chronic fighting experience generalized to other behaviors, such as gap-crossing and courtship. We propose that in response to repeatedly winning or losing aggressive encounters, male flies form an internal state that displays persistence and generalization; fight outcomes can also have positive or negative valence. Furthermore, we show that the activities of the PPL1-γ1pedc dopaminergic neuron and the MBON-γ1pedc\>α/β mushroom body output neuron are required for aversion to an olfactory cue associated with losing fights.

}, issn = {1091-6490}, doi = {10.1073/pnas.1716612115}, author = {Kim, Yong-Kyu and Saver, Mathias and Simon, Jasper and Kent, Clement F and Shao, Lisha and Eddison, Mark and Agrawal, Pavan and Texada, Michael and Truman, James W and Heberlein, Ulrike} } @article {49485, title = {Social isolation-induced epigenetic and transcriptional changes in Drosophila dopaminergic neurons.}, journal = {bioRxiv}, year = {2018}, month = {2018 Oct 14}, abstract = {Epigenetic mechanisms play fundamental roles in brain function and behavior and stressors such as social isolation can alter animal behavior via epigenetic mechanisms. However, due to cellular heterogeneity, identifying cell-type-specific epigenetic changes in the brain is challenging. Here we report first use of a modified INTACT method in behavioral epigenetics of Drosophila: a method we call mini-INTACT. Using ChIP-seq on mini-INTACT purified dopaminergic nuclei, we identified epigenetic signatures in socially-isolated and socially-enriched Drosophila males. Social experience altered the epigenetic landscape in clusters of genes involved in transcription and neural function. Some of these alterations were predicted by expression changes of four transcription factors and the prevalence of their binding sites in several clusters. These transcription factors were previously identified as activity-regulated genes and their knockdown in dopaminergic neurons reduced the effects of social experience on sleep. Our work enables the use of Drosophila as a model for cell-type-specific behavioral epigenetics. }, doi = {10.1101/443226}, author = {Agrawal, Pavan and Chung, Phuong and Heberlein, Ulrike and Kent, Clement F} } @article {48786, title = {Dissection of the Drosophila neuropeptide F circuit using a high-throughput two-choice assay.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, year = {2017}, month = {2017 Sep 05}, pages = {e8091-9}, abstract = {

In their classic experiments, Olds and Milner showed that rats learn to lever press to receive an electric stimulus in specific brain regions. This led to the identification of mammalian reward centers. Our interest in defining the neuronal substrates of reward perception in the fruit fly Drosophila melanogaster prompted us to develop a simpler experimental approach wherein flies could implement behavior that induces self-stimulation of specific neurons in their brains. The high-throughput assay employs optogenetic activation of neurons when the fly occupies a specific area of a behavioral chamber, and the flies{\textquoteright} preferential occupation of this area reflects their choosing to experience optogenetic stimulation. Flies in which neuropeptide F (NPF) neurons are activated display preference for the illuminated side of the chamber. We show that optogenetic activation of NPF neuron is rewarding in olfactory conditioning experiments and that the preference for NPF neuron activation is dependent on NPF signaling. Finally, we identify a small subset of NPF-expressing neurons located in the dorsomedial posterior brain that are sufficient to elicit preference in our assay. This assay provides the means for carrying out unbiased screens to map reward neurons in flies.

}, issn = {1091-6490}, doi = {10.1073/pnas.1710552114}, author = {Shao, Lisha and Saver, Mathias and Chung, Phuong and Ren, Qingzhong and Lee, Tzumin and Kent, Clement F and Heberlein, Ulrike} } @article {47039, title = {A subset of serotonergic neurons evokes hunger in adult Drosophila.}, journal = {Current Biology : CB}, volume = {25}, year = {2015}, month = {2015 Sep 2}, pages = {2435-40}, abstract = {

Hunger is a complex motivational state that drives multiple behaviors. The sensation of hunger is caused by an imbalance between energy intake and expenditure. One immediate response to hunger is increased food consumption. Hunger also modulates behaviors related to food seeking such as increased locomotion and enhanced sensory sensitivity in both insects [1-5] and vertebrates [6, 7]. In addition, hunger can promote the expression of food-associated memory [8, 9]. Although progress is being made [10], how hunger is represented in the brain and how it coordinates these behavioral responses is not fully understood in any system. Here, we use Drosophila melanogaster to identify neurons encoding hunger. We found a small group of neurons that, when activated, induced a fed fly to eat as though it were starved, suggesting that these neurons are downstream of the metabolic regulation of hunger. Artificially activating these neurons also promotes appetitive memory performance in sated flies, indicating that these neurons are not simply feeding command neurons but likely play a more general role in encoding hunger. We determined that the neurons relevant for the feeding effect are serotonergic and project broadly within the brain, suggesting a possible mechanism for how various responses to hunger are coordinated. These findings extend our\ understanding of the neural circuitry that drives feeding and enable future exploration of how state influences neural activity within this circuit.

}, issn = {1879-0445}, doi = {10.1016/j.cub.2015.08.005}, author = {Albin, Stephanie D and Kaun, Karla R and Knapp, Jon-Michael and Chung, Phuong and Heberlein, Ulrike and Simpson, Julie H} } @article {46595, title = {EGFR and FGFR pathways have distinct roles in Drosophila mushroom body development and ethanol-induced behavior.}, journal = {PLoS One}, volume = {9}, year = {2014}, month = {2014 Jan 31}, pages = {e87714}, abstract = {

Epidermal Growth Factor Receptor (EGFR) signaling has a conserved role in ethanol-induced behavior in flies and mice, affecting ethanol-induced sedation in both species. However it is not known what other effects EGFR signaling may have on ethanol-induced behavior, or what roles other Receptor Tyrosine Kinase (RTK) pathways may play in ethanol induced behaviors. We examined the effects of both the EGFR and Fibroblast Growth Factor Receptor (FGFR) RTK signaling pathways on ethanol-induced enhancement of locomotion, a behavior distinct from sedation that may be associated with the rewarding effects of ethanol. We find that both EGFR and FGFR genes influence ethanol-induced locomotion, though their effects are opposite - EGFR signaling suppresses this behavior, while FGFR signaling promotes it. EGFR signaling affects development of the Drosophila mushroom bodies in conjunction with the JNK MAP kinase basket (bsk), and with the Ste20 kinase tao, and we hypothesize that the EGFR pathway affects ethanol-induced locomotion through its effects on neuronal development. We find, however, that FGFR signaling most likely affects ethanol-induced behavior through a different mechanism, possibly through acute action in adult neurons.

}, keywords = {Animals, Behavior, Animal, Central Nervous System Depressants, Drosophila melanogaster, Drosophila Proteins, Ethanol, Locomotion, Mice, Mushroom Bodies, Receptor, Epidermal Growth Factor, Receptors, Invertebrate Peptide, Signal Transduction}, issn = {1932-6203}, doi = {10.1371/journal.pone.0087714}, author = {King, Ian F G and Eddison, Mark and Kaun, Karla R and Heberlein, Ulrike} } @article {45811, title = {Mushroom body output neurons encode valence and guide memory-based action selection in Drosophila.}, journal = {eLife}, volume = {4}, year = {2014}, month = {12/2014}, abstract = {

Animals discriminate stimuli, learn their predictive value and use this knowledge to modify their behavior. In Drosophila, the mushroom body (MB) plays a key role in these processes. Sensory stimuli are sparsely represented by \~{}2000 Kenyon cells, which converge onto 34 output neurons (MBONs) of 21 types. We studied the role of MBONs in several associative learning tasks and in sleep regulation, revealing the extent to which information flow is segregated into distinct channels and suggesting possible roles for the multi-layered MBON network. We also show that optogenetic activation of MBONs can, depending on cell type, induce repulsion or attraction in flies. The behavioral effects of MBON perturbation are combinatorial, suggesting that the MBON ensemble collectively represents valence. We propose that local, stimulus-specific dopaminergic modulation selectively alters the balance within the MBON network for those stimuli. Our results suggest that valence encoded by the MBON ensemble biases memory-based action selection.

}, issn = {2050-084X}, doi = {10.7554/eLife.04580}, author = {Aso, Yoshinori and Sitaraman, Divya and Ichinose, Toshiharu and Kaun, Karla R and Vogt, Katrin and Belliart-Gu{\'e}rin, Ghislain and Placais, Pierre-Yves and Robie, Alice A and Yamagata, Nobuhiro and Schnaitmann, Christopher and Rowell, William J and Johnston, Rebecca M and Ngo, Teri-T B and Chen, Nan and Korff, Wyatt and Nitabach, Michael N and Heberlein, Ulrike and Preat, Thomas and Branson, Kristin M and Tanimoto, Hiromu and Rubin, Gerald M} } @article {6534, title = {Addiction.}, journal = {Current Opinion in Neurobiology}, volume = {23}, year = {2013}, month = {2013 Aug}, pages = {463-6}, abstract = {

Drug addiction and obesity share the core feature that those afflicted by the disorders express a desire to limit drug or food consumption yet persist despite negative consequences. Emerging evidence suggests that the compulsivity that defines these disorders may arise, to some degree at least, from common underlying neurobiological mechanisms. In particular, both disorders are associated with diminished striatal dopamine D2 receptor (D2R) availability, likely reflecting their decreased maturation and surface expression. In striatum, D2Rs are expressed by approximately half of the principal medium spiny projection neurons (MSNs), the striatopallidal neurons of the so-called {\textquoteright}indirect{\textquoteright} pathway. D2Rs are also expressed presynaptically on dopamine terminals and on cholinergic interneurons. This heterogeneity of D2R expression has hindered attempts, largely using traditional pharmacological approaches, to understand their contribution to compulsive drug or food intake. The emergence of genetic technologies to target discrete populations of neurons, coupled to optogenetic and chemicogenetic tools to manipulate their activity, have provided a means to dissect striatopallidal and cholinergic contributions to compulsivity. Here, we review recent evidence supporting an important role for striatal D2R signaling in compulsive drug use and food intake. We pay particular attention to striatopallidal projection neurons and their role in compulsive responding for food and drugs. Finally, we identify opportunities for future obesity research using known mechanisms of addiction as a heuristic, and leveraging new tools to manipulate activity of specific populations of striatal neurons to understand their contributions to addiction and obesity.

}, issn = {1873-6882}, doi = {10.1016/j.conb.2013.07.003}, author = {Everitt, Barry J and Heberlein, Ulrike} } @article {46596, title = {Competing dopamine neurons drive oviposition choice for ethanol in Drosophila.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {110}, year = {2013}, month = {2013 Dec 24}, pages = {21153-8}, abstract = {

The neural circuits that mediate behavioral choice evaluate and integrate information from the environment with internal demands and then initiate a behavioral response. Even circuits that support simple decisions remain poorly understood. In Drosophila melanogaster, oviposition on a substrate containing ethanol enhances fitness; however, little is known about the neural mechanisms mediating this important choice behavior. Here, we characterize the neural modulation of this simple choice and show that distinct subsets of dopaminergic neurons compete to either enhance or inhibit egg-laying preference for ethanol-containing food. Moreover, activity in α{\textquoteright}β{\textquoteright} neurons of the mushroom body and a subset of ellipsoid body ring neurons (R2) is required for this choice. We propose a model where competing dopaminergic systems modulate oviposition preference to adjust to changes in natural oviposition substrates.

}, keywords = {Analysis of Variance, Animals, Choice Behavior, Dopaminergic Neurons, Drosophila melanogaster, Ethanol, Female, Fermentation, Fruit, Mushroom Bodies, Oviposition}, issn = {1091-6490}, doi = {10.1073/pnas.1320208110}, author = {Azanchi, Reza and Kaun, Karla R and Heberlein, Ulrike} } @article {46599, title = {The evolution of Drosophila melanogaster as a model for alcohol research.}, journal = {Annual Reviews of Neuroscience}, volume = {36}, year = {2013}, month = {2013 Jul 8}, pages = {121-38}, abstract = {

Animal models have been widely used to gain insight into the mechanisms underlying the acute and long-term effects of alcohol exposure. The fruit fly Drosophila melanogaster encounters ethanol in its natural habitat and possesses many adaptations that allow it to survive and thrive in ethanol-rich environments. Several assays to study ethanol-related behaviors in flies, ranging from acute intoxication to self-administration and reward, have been developed in the past 20 years. These assays have provided the basis for studying the physiological and behavioral effects of ethanol and for identifying genes mediating these effects. In this review we describe the ecological relationship between flies and ethanol, the effects of ethanol on fly development and behavior, the use of flies as a model for alcohol addiction, and the interaction between ethanol and social behavior. We discuss these advances in the context of their utility to help decipher the mechanisms underlying the diverse effects of ethanol, including those that mediate ethanol dependence and addiction in humans.

}, keywords = {Alcoholism, Animals, Biological Evolution, Disease Models, Animal, Drosophila melanogaster, Ethanol, Humans, Reward, Self Administration}, issn = {1545-4126}, doi = {10.1146/annurev-neuro-062012-170256}, author = {Devineni, Anita V and Heberlein, Ulrike} } @article {46597, title = {The novel gene tank, a tumor suppressor homolog, regulates ethanol sensitivity in Drosophila.}, journal = {The Journal of Neuroscience}, volume = {33}, year = {2013}, month = {2013 May 8}, pages = {8134-43}, abstract = {

In both mammalian and insect models of ethanol intoxication, high doses of ethanol induce motor impairment and eventually sedation. Sensitivity to the sedative effects of ethanol is inversely correlated with risk for alcoholism. However, the genes regulating ethanol sensitivity are largely unknown. Based on a previous genetic screen in Drosophila for ethanol sedation mutants, we identified a novel gene, tank (CG15626), the homolog of the mammalian tumor suppressor EI24/PIG8, which has a strong role in regulating ethanol sedation sensitivity. Genetic and behavioral analyses revealed that tank acts in the adult nervous system to promote ethanol sensitivity. We localized the function of tank in regulating ethanol sensitivity to neurons within the pars intercerebralis that have not been implicated previously in ethanol responses. We show that acutely manipulating the activity of all tank-expressing neurons, or of pars intercerebralis neurons in particular, alters ethanol sensitivity in a sexually dimorphic manner, since neuronal activation enhanced ethanol sedation in males, but not females. Finally, we provide anatomical evidence that tank-expressing neurons form likely synaptic connections with neurons expressing the neural sex determination factor fruitless (fru), which have been implicated recently in the regulation of ethanol sensitivity. We suggest that a functional interaction with fru neurons, many of which are sexually dimorphic, may account for the sex-specific effect induced by activating tank neurons. Overall, we have characterized a novel gene and corresponding set of neurons that regulate ethanol sensitivity in Drosophila.

}, keywords = {Adaptor Proteins, Signal Transducing, Analysis of Variance, Animals, Animals, Genetically Modified, Apoptosis Regulatory Proteins, Behavior, Animal, Central Nervous System Depressants, Dose-Response Relationship, Drug, Drosophila, Drosophila Proteins, Ethanol, Gene Expression Regulation, Green Fluorescent Proteins, Humans, Molecular Biology, Mutation, Nuclear Proteins, RNA Interference, TRPC Cation Channels, Tumor Suppressor Proteins}, issn = {1529-2401}, doi = {10.1523/JNEUROSCI.3695-12.2013}, author = {Devineni, Anita V and Eddison, Mark and Heberlein, Ulrike} } @article {46601, title = {A small group of neurosecretory cells expressing the transcriptional regulator apontic and the neuropeptide corazonin mediate ethanol sedation in Drosophila.}, journal = {The Journal of Neuroscience}, volume = {33}, year = {2013}, month = {2013 Feb 27}, pages = {4044-54}, abstract = {

In the fruit fly Drosophila melanogaster, as in mammals, acute exposure to a high dose of ethanol leads to stereotypical behavioral changes beginning with increased activity, followed by incoordination, loss of postural control, and eventually, sedation. The mechanism(s) by which ethanol impacts the CNS leading to ethanol-induced sedation and the genes required for normal sedation sensitivity remain largely unknown. Here we identify the gene apontic (apt), an Myb/SANT-containing transcription factor that is required in the nervous system for normal sensitivity to ethanol sedation. Using genetic and behavioral analyses, we show that apt mediates sensitivity to ethanol sedation by acting in a small set of neurons that express Corazonin (Crz), a neuropeptide likely involved in the physiological response to stress. The activity of Crz neurons regulates the behavioral response to ethanol, as silencing and activating these neurons affects sedation sensitivity in opposite ways. Furthermore, this effect is mediated by Crz, as flies with reduced crz expression show reduced sensitivity to ethanol sedation. Finally, we find that both apt and crz are rapidly upregulated by acute ethanol exposure. Thus, we have identified two genes and a small set of peptidergic neurons that regulate sensitivity to ethanol-induced sedation. We propose that Apt regulates the activity of Crz neurons and/or release of the neuropeptide during ethanol exposure.

}, keywords = {Animals, Animals, Genetically Modified, Behavior, Animal, Brain, DNA-Binding Proteins, Dose-Response Relationship, Drug, Drosophila, Drosophila Proteins, Ethanol, Gene Expression Regulation, Green Fluorescent Proteins, Hypnotics and Sedatives, Metamorphosis, Biological, Mutation, Neurons, Neuropeptides, Neurosecretory Systems, RNA, Messenger, Transcription Factors}, issn = {1529-2401}, doi = {10.1523/JNEUROSCI.3413-12.2013}, author = {McClure, Kimberly D and Heberlein, Ulrike} } @article {46604, title = {Acute ethanol responses in Drosophila are sexually dimorphic.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {109}, year = {2012}, month = {2012 Dec 18}, pages = {21087-92}, abstract = {

In mammalian and insect models of ethanol intoxication, low doses of ethanol stimulate locomotor activity whereas high doses induce sedation. Sex differences in acute ethanol responses, which occur in humans, have not been characterized in Drosophila. In this study, we find that male flies show increased ethanol hyperactivity and greater resistance to ethanol sedation compared with females. We show that the sex determination gene transformer (tra) acts in the developing nervous system, likely through regulation of fruitless (fru), to at least partially mediate the sexual dimorphism in ethanol sedation. Although pharmacokinetic differences may contribute to the increased sedation sensitivity of females, neuronal tra expression regulates ethanol sedation independently of ethanol pharmacokinetics. We also show that acute activation of fru-expressing neurons affects ethanol sedation, further supporting a role for fru in regulating this behavior. Thus, we have characterized previously undescribed sex differences in behavioral responses to ethanol, and implicated fru in mediating a subset of these differences.

}, keywords = {Alcoholic Intoxication, Animals, Central Nervous System Stimulants, Crosses, Genetic, Disease Models, Animal, Drosophila melanogaster, Ethanol, Female, Gene Expression Regulation, Male, Models, Statistical, Neurons, Sex Characteristics, Sex Factors}, issn = {1091-6490}, doi = {10.1073/pnas.1218850110}, author = {Devineni, Anita V and Heberlein, Ulrike} } @article {46605, title = {DlgS97/SAP97, a neuronal isoform of discs large, regulates ethanol tolerance.}, journal = {PLoS One}, volume = {7}, year = {2012}, month = {2012 Nov 7}, pages = {e48967}, abstract = {

From a genetic screen for Drosophila melanogaster mutants with altered ethanol tolerance, we identified intolerant (intol), a novel allele of discs large 1 (dlg1). Dlg1 encodes Discs Large 1, a MAGUK (Membrane Associated Guanylate Kinase) family member that is the highly conserved homolog of mammalian PSD-95 and SAP97. The intol mutation disrupted specifically the expression of DlgS97, a SAP97 homolog, and one of two major protein isoforms encoded by dlg1 via alternative splicing. Expression of the major isoform, DlgA, a PSD-95 homolog, appeared unaffected. Ethanol tolerance in the intol mutant could be partially restored by transgenic expression of DlgS97, but not DlgA, in specific neurons of the fly{\textquoteright}s brain. Based on co-immunoprecipitation, DlgS97 forms a complex with N-methyl-D-aspartate (NMDA) receptors, a known target of ethanol. Consistent with these observations, flies expressing reduced levels of the essential NMDA receptor subunit dNR1 also showed reduced ethanol tolerance, as did mutants in the gene calcium/calmodulin-dependent protein kinase (caki), encoding the fly homolog of mammalian CASK, a known binding partner of DlgS97. Lastly, mice in which SAP97, the mammalian homolog of DlgS97, was conditionally deleted in adults failed to develop rapid tolerance to ethanol{\textquoteright}s sedative/hypnotic effects. We propose that DlgS97/SAP97 plays an important and conserved role in the development of tolerance to ethanol via NMDA receptor-mediated synaptic plasticity.

}, keywords = {Alleles, Alternative Splicing, Animals, Drosophila melanogaster, Drosophila Proteins, Ethanol, Female, Guanylate Kinase, Male, Membrane Proteins, Mice, Mice, Inbred C57BL, Mutation, Neurons, Protein Isoforms, Receptors, N-Methyl-D-Aspartate, Repressor Proteins, Tumor Suppressor Proteins}, issn = {1932-6203}, doi = {10.1371/journal.pone.0048967}, author = {Maiya, Rajani and Lee, Seonok and Berger, Karen H and Kong, Eric C and Slawson, Justin B and Griffith, Leslie C and Takamiya, Kogo and Huganir, Richard L and Margolis, Ben and Heberlein, Ulrike} } @article {4522, title = {Drosophila melanogaster as a model to study drug addiction.}, journal = {Human Genetics}, volume = {131}, year = {2012}, month = {2012 Feb 17}, pages = {959-75}, abstract = {

Animal studies have been instrumental in providing knowledge about the molecular and neural mechanisms underlying drug addiction. Recently, the fruit fly Drosophila melanogaster has become a valuable system to model not only the acute stimulating and sedating effects of drugs but also their more complex rewarding properties. In this review, we describe the advantages of using the fly to study drug-related behavior, provide a brief overview of the behavioral assays used, and review the molecular mechanisms and neural circuits underlying drug-induced behavior in flies. Many of these mechanisms have been validated in mammals, suggesting that the fly is a useful model to understand the mechanisms underlying addiction.

}, issn = {1432-1203}, doi = {10.1007/s00439-012-1146-6}, author = {Kaun, Karla R and Devineni, Anita V and Heberlein, Ulrike} } @article {46602, title = {A genetic screen for olfactory habituation mutations in Drosophila: analysis of novel foraging alleles and an underlying neural circuit.}, journal = {PLoS One}, volume = {7}, year = {2012}, month = {2012 Dec 17}, pages = {e51684}, abstract = {

Habituation is a form of non-associative learning that enables animals to reduce their reaction to repeated harmless stimuli. When exposed to ethanol vapor, Drosophila show an olfactory-mediated startle response characterized by a transient increase in locomotor activity. Upon repeated exposures, this olfactory startle attenuates with the characteristics of habituation. Here we describe the results of a genetic screen to identify olfactory startle habituation (OSH) mutants. One mutation is a transcript specific allele of foraging (for) encoding a cGMP-dependent kinase. We show this allele of for reduces expression of a for-T1 isoform expressed in the head and functions normally to inhibit OSH. We localize for-T1 function to a limited set of neurons that include olfactory receptor neurons (ORNs) and the mushroom body (MB). Overexpression of for-T1 in ORNs inhibits OSH, an effect also seen upon synaptic silencing of the ORNs; for-T1 may therefore function in ORNs to decrease synaptic release upon repeated exposure to ethanol vapor. Overall, this work contributes to our understanding of the genes and neurons underlying olfactory habituation in Drosophila.

}, keywords = {Alleles, Animals, Anti-Infective Agents, Local, Cyclic GMP-Dependent Protein Kinases, Drosophila melanogaster, Drosophila Proteins, Ethanol, Genetic Testing, Habituation, Psychophysiologic, Mushroom Bodies, Mutation, Neurons, Olfactory Receptor Neurons, Reaction Time, Reflex, Startle, Smell}, issn = {1932-6203}, doi = {10.1371/journal.pone.0051684}, author = {Eddison, Mark and Belay, Amsale T and Sokolowski, Marla B and Heberlein, Ulrike} } @article {46603, title = {JNK pathway activation is controlled by Tao/TAOK3 to modulate ethanol sensitivity.}, journal = {PLoS One}, volume = {7}, year = {2012}, month = {2012 Dec 5}, pages = {e50594}, abstract = {

Neuronal signal transduction by the JNK MAP kinase pathway is altered by a broad array of stimuli including exposure to the widely abused drug ethanol, but the behavioral relevance and the regulation of JNK signaling is unclear. Here we demonstrate that JNK signaling functions downstream of the Sterile20 kinase family gene tao/Taok3 to regulate the behavioral effects of acute ethanol exposure in both the fruit fly Drosophila and mice. In flies tao is required in neurons to promote sensitivity to the locomotor stimulant effects of acute ethanol exposure and to establish specific brain structures. Reduced expression of key JNK pathway genes substantially rescued the structural and behavioral phenotypes of tao mutants. Decreasing and increasing JNK pathway activity resulted in increased and decreased sensitivity to the locomotor stimulant properties of acute ethanol exposure, respectively. Further, JNK expression in a limited pattern of neurons that included brain regions implicated in ethanol responses was sufficient to restore normal behavior. Mice heterozygous for a disrupted allele of the homologous Taok3 gene (Taok3Gt) were resistant to the acute sedative effects of ethanol. JNK activity was constitutively increased in brains of Taok3Gt/+ mice, and acute induction of phospho-JNK in brain tissue by ethanol was occluded in Taok3Gt/+ mice. Finally, acute administration of a JNK inhibitor conferred resistance to the sedative effects of ethanol in wild-type but not Taok3Gt/+ mice. Taken together, these data support a role of a TAO/TAOK3-JNK neuronal signaling pathway in regulating sensitivity to acute ethanol exposure in flies and in mice.

}, keywords = {Animals, Base Sequence, Behavior, Animal, DNA Primers, Drosophila, Drosophila Proteins, Ethanol, Immunohistochemistry, MAP Kinase Kinase 4, Mice, Mice, Inbred C57BL, Mutation, Protein-Serine-Threonine Kinases, Reverse Transcriptase Polymerase Chain Reaction}, issn = {1932-6203}, doi = {10.1371/journal.pone.0050594}, author = {Kapfhamer, David and King, Ian and Zou, Mimi E and Lim, Jana P and Heberlein, Ulrike and Wolf, Fred W} } @article {46607, title = {Lmo4 in the basolateral complex of the amygdala modulates fear learning.}, journal = {PLoS One}, volume = {7}, year = {2012}, month = {2012 Apr 3}, pages = {e34559}, abstract = {

Pavlovian fear conditioning is an associative learning paradigm in which mice learn to associate a neutral conditioned stimulus with an aversive unconditioned stimulus. In this study, we demonstrate a novel role for the transcriptional regulator Lmo4 in fear learning. LMO4 is predominantly expressed in pyramidal projection neurons of the basolateral complex of the amygdala (BLC). Mice heterozygous for a genetrap insertion in the Lmo4 locus (Lmo4gt/+), which express 50\% less Lmo4 than their wild type (WT) counterparts display enhanced freezing to both the context and the cue in which they received the aversive stimulus. Small-hairpin RNA-mediated knockdown of Lmo4 in the BLC, but not the dentate gyrus region of the hippocampus recapitulated this enhanced conditioning phenotype, suggesting an adult- and brain region-specific role for Lmo4 in fear learning. Immunohistochemical analyses revealed an increase in the number of c-Fos positive puncta in the BLC of Lmo4gt/+ mice in comparison to their WT counterparts after fear conditioning. Lastly, we measured anxiety-like behavior in Lmo4gt/+ mice and in mice with BLC-specific downregulation of Lmo4 using the elevated plus maze, open field, and light/dark box tests. Global or BLC-specific knockdown of Lmo4 did not significantly affect anxiety-like behavior. These results suggest a selective role for LMO4 in the BLC in modulating learned but not unlearned fear.

}, keywords = {Adaptor Proteins, Signal Transducing, Amygdala, Animals, Behavior, Animal, Conditioning (Psychology), Cues, Fear, Gene Knockdown Techniques, LIM Domain Proteins, Male, Mice, Mice, Inbred C57BL, Neurons, Protein Transport}, issn = {1932-6203}, doi = {10.1371/journal.pone.0034559}, author = {Maiya, Rajani and Kharazia, Viktor and Lasek, Amy W and Heberlein, Ulrike} } @article {5482, title = {Tissue-specific activation of a single gustatory receptor produces opposing behavioral responses in Drosophila.}, journal = {Genetics}, volume = {192}, year = {2012}, month = {2012 Oct}, pages = {521-32}, abstract = {

Understanding sensory systems that perceive environmental inputs and neural circuits that select appropriate motor outputs is essential for studying how organisms modulate behavior and make decisions necessary for survival. Drosophila melanogaster oviposition is one such important behavior, in which females evaluate their environment and choose to lay eggs on substrates they may find aversive in other contexts. We employed neurogenetic techniques to characterize neurons that influence the choice between repulsive positional and attractive egg-laying responses toward the bitter-tasting compound lobeline. Surprisingly, we found that neurons expressing Gr66a, a gustatory receptor normally involved in avoidance behaviors, receive input for both attractive and aversive preferences. We hypothesized that these opposing responses may result from activation of distinct Gr66a-expressing neurons. Using tissue-specific rescue experiments, we found that Gr66a-expressing neurons on the legs mediate positional aversion. In contrast, pharyngeal taste cells mediate the egg-laying attraction to lobeline, as determined by analysis of mosaic flies in which subsets of Gr66a neurons were silenced. Finally, inactivating mushroom body neurons disrupted both aversive and attractive responses, suggesting that this brain structure is a candidate integration center for decision-making during Drosophila oviposition. We thus define sensory and central neurons critical to the process by which flies decide where to lay an egg. Furthermore, our findings provide insights into the complex nature of gustatory perception in Drosophila. We show that tissue-specific activation of bitter-sensing Gr66a neurons provides one mechanism by which the gustatory system differentially encodes aversive and attractive responses, allowing the female fly to modulate her behavior in a context-dependent manner.

}, issn = {1943-2631}, doi = {10.1534/genetics.112.142455}, author = {Joseph, Ryan M and Heberlein, Ulrike} } @article {5483, title = {Alk is a transcriptional target of LMO4 and ERα that promotes cocaine sensitization and reward.}, journal = {The Journal of Neuroscience: The Official Journal of the Society for Neuroscience}, volume = {31}, year = {2011}, month = {2011 Oct 5}, pages = {14134-41}, abstract = {

Previously, we showed that the mouse LIM-domain only 4 (Lmo4) gene, which encodes a protein containing two zinc-finger LIM domains that interact with various DNA-binding transcription factors, attenuates behavioral sensitivity to repeated cocaine administration. Here we show that transcription of anaplastic lymphoma kinase (Alk) is repressed by LMO4 in the striatum and that Alk promotes the development of cocaine sensitization and conditioned place preference, a measure of cocaine reward. Since LMO4 is known to interact with estrogen receptor α (ERα) at the promoters of target genes, we investigated whether Alk expression might be controlled by a similar mechanism. We found that LMO4 and ERα are associated with the Alk promoter by chromatin immunoprecipitation and that Alk is an estrogen-responsive gene in the striatum. Moreover, we show that ERα knock-out mice exhibit enhanced cocaine sensitization and conditioned place preference and an increase in Alk expression in the nucleus accumbens. These data define a novel regulatory network involved in behavioral responses to cocaine. Interestingly, sex differences in several behavioral responses to cocaine in humans and rodents have been described, and estrogen is thought to mediate some of these differences. Our data suggest that estrogen regulation of Alk may be one mechanism responsible for sexually dimorphic responses to cocaine.

}, keywords = {Adaptor Proteins, Animals, Cells, Cocaine, Cultured, Estrogen Receptor alpha, Gene Targeting, Genetic, HEK293 Cells, Humans, Inbred C57BL, Knockout, LIM Domain Proteins, Male, Mice, Motor Activity, Newborn, Receptor Protein-Tyrosine Kinases, Reward, Signal Transducing, Transcription}, issn = {1529-2401}, doi = {10.1523/JNEUROSCI.3415-11.2011}, author = {Lasek, Amy W and Gesch, Julie and Giorgetti, Francesco and Kharazia, Viktor and Heberlein, Ulrike} } @article {4523, title = {Arouser reveals a role for synapse number in the regulation of ethanol sensitivity.}, journal = {Neuron}, volume = {70}, year = {2011}, month = {2011 Jun 9}, pages = {979-90}, abstract = {

A reduced sensitivity to the sedating effects of alcohol is a characteristic associated with alcohol use disorders (AUDs). A genetic screen for ethanol sedation mutants in Drosophila identified arouser (aru), which functions in developing neurons to reduce ethanol sensitivity. Genetic evidence suggests that aru regulates ethanol sensitivity through its activation by Egfr/Erk signaling and its inhibition by PI3K/Akt signaling. The aru mutant also has an increased number of synaptic terminals in the larva and adult fly. Both the increased ethanol sensitivity and synapse number of the aru mutant are restored upon adult social isolation, suggesting a causal relationship between synapse number and ethanol sensitivity. We thus show that a developmental abnormality affecting synapse number and ethanol sensitivity is not permanent and can be reversed by manipulating the environment of the adult fly.

}, keywords = {Adaptor Proteins, Animal, Animals, Arabidopsis Proteins, Behavior, Brain, Central Nervous System Depressants, Developmental, Drosophila, Drosophila Proteins, Epidermal Growth Factor, Ethanol, Gene Expression Regulation, Genetically Modified, Green Fluorescent Proteins, Invertebrate Peptide, Larva, Mutation, Neuromuscular Junction, Neurons, Phosphatidylinositol 3-Kinases, Receptor, Receptors, Reflex, RNA Interference, Signal Transducing, Signal Transduction, Social Isolation, Synapses}, issn = {1097-4199}, doi = {10.1016/j.neuron.2011.03.030}, author = {Eddison, Mark and Guarnieri, Douglas J and Cheng, Ling and Liu, Che-Hsiung and Moffat, Kevin G and Davis, Graeme and Heberlein, Ulrike} } @article {4524, title = {A Drosophila model for alcohol reward.}, journal = {Nature Neuroscience}, volume = {14}, year = {2011}, month = {2011 May}, pages = {612-9}, abstract = {

The rewarding properties of drugs contribute to the development of abuse and addiction. We developed a new assay for investigating the motivational properties of ethanol in the genetically tractable model Drosophila melanogaster. Flies learned to associate cues with ethanol intoxication and, although transiently aversive, the experience led to a long-lasting attraction for the ethanol-paired cue, implying that intoxication is rewarding. Temporally blocking transmission in dopaminergic neurons revealed that flies require activation of these neurons to express, but not develop, conditioned preference for ethanol-associated cues. Moreover, flies acquired, consolidated and retrieved these rewarding memories using distinct sets of neurons in the mushroom body. Finally, mutations in scabrous, encoding a fibrinogen-related peptide that regulates Notch signaling, disrupted the formation of memories for ethanol reward. Our results thus establish that Drosophila can be useful for understanding the molecular, genetic and neural mechanisms underling the rewarding properties of ethanol.

}, keywords = {Alcohol-Related Disorders, Alcohols, Analysis of Variance, Animal, Animals, Behavior, Chromatography, Conditioning (Psychology), Disease Models, Dopamine, Drosophila, Drosophila Proteins, Electric Stimulation, Ethanol, Food Preferences, Genetically Modified, Green Fluorescent Proteins, High Pressure Liquid, Male, Maze Learning, Mushroom Bodies, Neurons, Odors, Reward, Synaptic Transmission, Time Factors, Tyrosine 3-Monooxygenase}, issn = {1546-1726}, doi = {10.1038/nn.2805}, author = {Kaun, Karla R and Azanchi, Reza and Maung, Zaw and Hirsh, Jay and Heberlein, Ulrike} } @article {5484, title = {A Drosophila model for fetal alcohol syndrome disorders: role for the insulin pathway.}, journal = {Disease Models \& Mechanisms}, volume = {4}, year = {2011}, month = {2011 May}, pages = {335-46}, abstract = {

Prenatal exposure to ethanol in humans results in a wide range of developmental abnormalities, including growth deficiency, developmental delay, reduced brain size, permanent neurobehavioral abnormalities and fetal death. Here we describe the use of Drosophila melanogaster as a model for exploring the effects of ethanol exposure on development and behavior. We show that developmental ethanol exposure causes reduced viability, developmental delay and reduced adult body size. We find that flies reared on ethanol-containing food have smaller brains and imaginal discs, which is due to reduced cell division rather than increased apoptosis. Additionally, we show that, as in mammals, flies reared on ethanol have altered responses to ethanol vapor exposure as adults, including increased locomotor activation, resistance to the sedating effects of the drug and reduced tolerance development upon repeated ethanol exposure. We have found that the developmental and behavioral defects are largely due to the effects of ethanol on insulin signaling; specifically, a reduction in Drosophila insulin-like peptide (Dilp) and insulin receptor expression. Transgenic expression of Dilp proteins in the larval brain suppressed both the developmental and behavioral abnormalities displayed by ethanol-reared adult flies. Our results thus establish Drosophila as a useful model system to uncover the complex etiology of fetal alcohol syndrome.

}, keywords = {Adaptation, Animal, Animals, Apoptosis, Behavior, Brain, Cell Proliferation, Disease Models, Drosophila melanogaster, Drosophila Proteins, Ethanol, Eye, Female, Fetal Alcohol Syndrome, Humans, Insulin, Larva, Physiological, Pregnancy, Receptor, Signal Transduction, Survival Analysis}, issn = {1754-8411}, doi = {10.1242/dmm.006411}, author = {McClure, Kimberly D and French, Rachael L and Heberlein, Ulrike} } @article {4525, title = {Drosophila tao controls mushroom body development and ethanol-stimulated behavior through par-1.}, journal = {The Journal of Neuroscience: The Official Journal of the Society for Neuroscience}, volume = {31}, year = {2011}, month = {2011 Jan 19}, pages = {1139-48}, abstract = {

In both mammalian and insect models of ethanol-induced behavior, low doses of ethanol stimulate locomotion. However, the mechanisms of the stimulant effects of ethanol on the CNS are mostly unknown. We have identified tao, encoding a serine-threonine kinase of the Ste20 family, as a gene necessary for ethanol-induced locomotor hyperactivity in Drosophila. Mutations in tao also affect behavioral responses to cocaine and nicotine, making flies resistant to the effects of both drugs. We show that tao function is required during the development of the adult nervous system and that tao mutations cause defects in the development of central brain structures, including the mushroom body. Silencing of a subset of mushroom body neurons is sufficient to reduce ethanol-induced hyperactivity, revealing the mushroom body as an important locus mediating the stimulant effects of ethanol. We also show that mutations in par-1 suppress both the mushroom body morphology and behavioral phenotypes of tao mutations and that the phosphorylation state of the microtubule-binding protein Tau can be altered by RNA interference knockdown of tao, suggesting that tao and par-1 act in a pathway to control microtubule dynamics during neural development.

}, keywords = {Analysis of Variance, Animal, Animals, Behavior, Biological, Blotting, Drosophila, Drosophila Proteins, Ethanol, Hyperkinesis, Immunohistochemistry, Metamorphosis, Motor Activity, Mushroom Bodies, Neurons, Protein-Serine-Threonine Kinases, Western}, issn = {1529-2401}, doi = {10.1523/JNEUROSCI.4416-10.2011}, author = {King, Ian and Tsai, Linus T-Y and Pflanz, Ralf and Voigt, Aaron and Lee, Seongsoo and J{\"a}ckle, Herbert and Lu, Bingwei and Heberlein, Ulrike} } @article {46610, title = {An evolutionary conserved role for anaplastic lymphoma kinase in behavioral responses to ethanol.}, journal = {PLoS One}, volume = {6}, year = {2011}, month = {2011 Jul 22}, pages = {e22636}, abstract = {

Anaplastic lymphoma kinase (Alk) is a gene expressed in the nervous system that encodes a receptor tyrosine kinase commonly known for its oncogenic function in various human cancers. We have determined that Alk is associated with altered behavioral responses to ethanol in the fruit fly Drosophila melanogaster, in mice, and in humans. Mutant flies containing transposon insertions in dAlk demonstrate increased resistance to the sedating effect of ethanol. Database analyses revealed that Alk expression levels in the brains of recombinant inbred mice are negatively correlated with ethanol-induced ataxia and ethanol consumption. We therefore tested Alk gene knockout mice and found that they sedate longer in response to high doses of ethanol and consume more ethanol than wild-type mice. Finally, sequencing of human ALK led to the discovery of four polymorphisms associated with a low level of response to ethanol, an intermediate phenotype that is predictive of future alcohol use disorders (AUDs). These results suggest that Alk plays an evolutionary conserved role in ethanol-related behaviors. Moreover, ALK may be a novel candidate gene conferring risk for AUDs as well as a potential target for pharmacological intervention.

}, keywords = {Alcohol Drinking, Alcoholics, Animals, Behavior, Animal, Conscious Sedation, Drosophila melanogaster, Drosophila Proteins, Ethanol, Evolution, Molecular, Female, Gene Expression Regulation, Enzymologic, Homeodomain Proteins, Humans, Male, Mice, Polymorphism, Genetic, Receptor Protein-Tyrosine Kinases}, issn = {1932-6203}, doi = {10.1371/journal.pone.0022636}, author = {Lasek, Amy W and Lim, Jana and Kliethermes, Christopher L and Berger, Karen H and Joslyn, Geoff and Brush, Gerry and Xue, Liquan and Robertson, Margaret and Moore, Monica S and Vranizan, Karen and Morris, Stephan W and Schuckit, Marc A and White, Raymond L and Heberlein, Ulrike} } @article {46611, title = {The genetic relationships between ethanol preference, acute ethanol sensitivity, and ethanol tolerance in Drosophila melanogaster.}, journal = {Fly (Austin)}, volume = {5}, year = {2011}, month = {2011 Jul-Sep}, pages = {191-9}, abstract = {

The relationship between alcohol consumption, sensitivity, and tolerance is an important question that has been addressed in humans and rodent models. Studies have shown that alcohol consumption and risk of abuse may correlate with (1) increased sensitivity to the stimulant effects of alcohol, (2) decreased sensitivity to the depressant effects of alcohol, and (3) increased alcohol tolerance. However, many conflicting results have been observed. To complement these studies, we utilized a different organism and approach to analyze the relationship between ethanol consumption and other ethanol responses. Using a set of 20 Drosophila melanogaster mutants that were isolated for altered ethanol sensitivity, we measured ethanol-induced hyperactivity, ethanol sedation, sedation tolerance, and ethanol consumption preference. Ethanol preference showed a strong positive correlation with ethanol tolerance, consistent with some rodent and human studies, but not with ethanol hyperactivity or sedation. No pairwise correlations were observed between ethanol hyperactivity, sedation, and tolerance. The evolutionary conservation of the relationship between tolerance and ethanol consumption in flies, rodents, and humans indicates that there are fundamental biological mechanisms linking specific ethanol responses.

}, keywords = {Alcohol Drinking, Alcoholic Intoxication, Animals, Central Nervous System Depressants, Drosophila melanogaster, Drosophila Proteins, Ethanol, Food Preferences, Hyperkinesis, Male, Transcription Factors}, issn = {1933-6942}, author = {Devineni, Anita V and McClure, Kimberly D and Guarnieri, Douglas J and Corl, Ammon B and Wolf, Fred W and Eddison, Mark and Heberlein, Ulrike} } @article {46608, title = {Insulin attenuates the acquisition and expression of ethanol-induced locomotor sensitization in DBA/2J mice.}, journal = {Life Sciences}, volume = {89}, year = {2011}, month = {2011 Dec 19}, pages = {968-74}, abstract = {

AIM: Ethanol-induced locomotor sensitization is a behavioral manifestation of physiological responses to repeated ethanol exposures. While ethanol exerts direct effects on multiple neurotransmitter systems in the brain, ethanol-induced changes in metabolic state, including acute hyperglycemia and inhibition of insulin signaling, also have plausible roles in the expression of ethanol-related behaviors through direct and indirect effects on brain function. The current experiments examined whether insulin administration or the resultant hypoglycemia might attenuate the development of sensitization to the locomotor stimulant effect of ethanol.

MAIN METHODS: Male and female DBA/2J mice received daily injections of 5 or 10 IU/kg insulin before or after a stimulating dose of ethanol and subsequent testing in an automated activity monitor. Blood glucose levels were determined upon the completion of the experiments.

KEY FINDINGS: Insulin injected prior to ethanol blunted the acute stimulant response as well as the acquisition and expression of locomotor sensitization, while insulin given after ethanol did not affect the development of the sensitized response. In a separate experiment, mice given glucose concurrently with insulin developed ethanol-induced locomotor sensitization normally.

SIGNIFICANCE: These experiments suggest that insulin attenuates the development of ethanol-induced locomotor sensitization, and that blood glucose levels can largely account for this effect. Further studies of the role of ethanol-induced metabolic states should provide novel information on the expression of ethanol-related behaviors.

}, keywords = {Animals, Behavior, Animal, Blood Glucose, Central Nervous System Depressants, Dose-Response Relationship, Drug, Ethanol, Female, Glucose, Hypoglycemia, Hypoglycemic Agents, Insulin, Male, Mice, Mice, Inbred DBA, Motor Activity}, issn = {1879-0631}, doi = {10.1016/j.lfs.2011.10.011}, author = {Kliethermes, Christopher L and Heberlein, Ulrike} } @article {46612, title = {Lmo genes regulate behavioral responses to ethanol in Drosophila melanogaster and the mouse.}, journal = {Alcoholism, Clinical and Experimental Research}, volume = {35}, year = {2011}, month = {2011 Sep}, pages = {1600-6}, abstract = {

BACKGROUND: Previous work from our laboratory demonstrated a role for the Drosophila Lim-only (dLmo) gene in regulating behavioral responses to cocaine. Herein, we examined whether dLmo influences the flies{\textquoteright} sensitivity to ethanol{\textquoteright}s sedating effects. We also investigated whether 1 of the mammalian homologs of dLmo, Lmo3, is involved in behavioral responses to ethanol in mice.

METHODS: To examine dLmo function in ethanol-induced sedation, mutant flies with reduced or increased dLmo expression were tested using the loss of righting (LOR) assay. To determine whether mouse Lmo3 regulates behavioral responses to ethanol, we generated transgenic mice expressing a short-hairpin RNA targeting Lmo3 for RNA interference-mediated knockdown by lentiviral infection of single cell embryos. Adult founder mice, expressing varying amounts of Lmo3 in the brain, were tested using ethanol loss-of-righting-reflex (LORR) and 2-bottle choice ethanol consumption assays.

RESULTS: We found that in flies, reduced dLmo activity increased sensitivity to ethanol-induced sedation, whereas increased expression of dLmo led to increased resistance to ethanol-induced sedation. In mice, reduced levels of Lmo3 were correlated with increased sedation time in the LORR test and decreased ethanol consumption in the 2-bottle choice protocol.

CONCLUSIONS: These data describe a novel and conserved role for Lmo genes in flies and mice in behavioral responses to ethanol. These studies also demonstrate the feasibility of rapidly translating findings from invertebrate systems to mammalian models of alcohol abuse by combining RNA interference in transgenic mice and behavioral testing.

}, keywords = {Adaptor Proteins, Signal Transducing, Animals, Behavior, Animal, Brain, Central Nervous System Depressants, Disease Models, Animal, Drosophila melanogaster, Drosophila Proteins, Ethanol, Female, Genotype, Green Fluorescent Proteins, Homeodomain Proteins, Hypnotics and Sedatives, LIM Domain Proteins, Male, Mice, Mice, Inbred C57BL, Mice, Transgenic, RNA, Small Interfering}, issn = {1530-0277}, doi = {10.1111/j.1530-0277.2011.01506.x}, author = {Lasek, Amy W and Giorgetti, Francesco and Berger, Karen H and Tayor, Stacy and Heberlein, Ulrike} } @article {46609, title = {Tao kinases as coordinators of actin and microtubule dynamics in developing neurons.}, journal = {Communicative \& Integrative Biology}, volume = {4}, year = {2011}, month = {2011 Sep}, pages = {554-6}, abstract = {

Drosophila tao, encoding a Ste20 family kinase, was identified as a gene involved in ethanol, cocaine and nicotine sensitivity. The behavioral phenotypes appear to be caused by defects in the development of the adult brain. Specifically, Drosophila tao functions to promote axon guidance of mushroom body (MB) neurons. The MB is a large structure in the central brain of the fly whose development and function have been well characterized. tao interacts genetically with mutations in the par-1 gene, also encoding a serine-threonine kinase. Since Par-1 has been implicated in the regulation of microtubule dynamics, this suggests that tao regulates the microtubule cytoskeleton in developing MB neurons. Here we discuss these results in light of previous studies that have proposed that Drosophila tao and its mammalian homologs function as a link between the actin and microtubule cytoskeletons, regulating microtubule stability in response to actin signals.

}, issn = {1942-0889}, doi = {10.4161/cib.4.5.16051}, author = {King, Ian and Heberlein, Ulrike} } @article {46615, title = {Addiction-like behavior in Drosophila.}, journal = {Communicative \& Integrative Biology}, volume = {3}, year = {2010}, month = {2010 Jul}, pages = {357-9}, abstract = {

Alcohol abuse is a pervasive problem known to be influenced by genetic factors, yet our understanding of the mechanisms underlying alcohol addiction is far from complete. Drosophila melanogaster has been established as a model for studying the molecular mechanisms that mediate the acute and chronic effects of alcohol. However, the Drosophila model has not yet been extended to include more complex alcohol-related behaviors such as self-administration. We recently established a paradigm to characterize ethanol consumption and preference in flies. We demonstrated that flies prefer to consume ethanol-containing food over regular food, and this preference exhibits several features of alcohol addiction: flies increase ethanol consumption over time, they consume ethanol to pharmacologically relevant concentrations, they will overcome an aversive stimulus in order to consume ethanol, and they exhibit relapse after a period of ethanol deprivation. Thus, ethanol preference in flies provides a new model for studying important aspects of addiction and their underlying mechanisms. One mutant that displayed decreased ethanol preference, krasavietz, may represent a first step toward uncovering those mechanisms.

}, issn = {1942-0889}, author = {Devineni, Anita V and Heberlein, Ulrike} } @article {46619, title = {Ethanol-regulated genes that contribute to ethanol sensitivity and rapid tolerance in Drosophila.}, journal = {Alcoholism, Clinical and Experimental Research}, volume = {34}, year = {2010}, month = {2010 Feb}, pages = {302-16}, abstract = {

BACKGROUND: Increased ethanol intake, a major predictor for the development of alcohol use disorders, is facilitated by the development of tolerance to both the aversive and pleasurable effects of the drug. The molecular mechanisms underlying ethanol tolerance development are complex and are not yet well understood.

METHODS: To identify genetic mechanisms that contribute to ethanol tolerance, we examined the time course of gene expression changes elicited by a single sedating dose of ethanol in Drosophila, and completed a behavioral survey of strains harboring mutations in ethanol-regulated genes.

RESULTS: Enrichment for genes in metabolism, nucleic acid binding, olfaction, regulation of signal transduction, and stress suggests that these biological processes are coordinately affected by ethanol exposure. We also detected a coordinate up-regulation of genes in the Toll and Imd innate immunity signal transduction pathways. A multi-study comparison revealed a small set of genes showing similar regulation, including increased expression of 3 genes for serine biosynthesis. A survey of Drosophila strains harboring mutations in ethanol-regulated genes for ethanol sensitivity and tolerance phenotypes revealed roles for serine biosynthesis, olfaction, transcriptional regulation, immunity, and metabolism. Flies harboring deletions of the genes encoding the olfactory co-receptor Or83b or the sirtuin Sir2 showed marked changes in the development of ethanol tolerance.

CONCLUSIONS: Our findings implicate novel roles for these genes in regulating ethanol behavioral responses.

}, keywords = {Animals, Behavior, Animal, Central Nervous System Depressants, Coenzyme A Ligases, Drosophila, Drosophila Proteins, Drug Tolerance, Ethanol, Female, Gene Expression Regulation, Histone Deacetylases, Male, Motor Activity, Mutation, Oligonucleotide Array Sequence Analysis, Receptors, Odorant, Reverse Transcriptase Polymerase Chain Reaction, Serpins, Sirtuins, Species Specificity}, issn = {1530-0277}, doi = {10.1111/j.1530-0277.2009.01093.x}, author = {Kong, Eric C and Allouche, Lorien and Chapot, Paul A and Vranizan, Karen and Moore, Monica S and Heberlein, Ulrike and Wolf, Fred W} } @article {46618, title = {A pair of dopamine neurons target the D1-like dopamine receptor DopR in the central complex to promote ethanol-stimulated locomotion in Drosophila.}, journal = {PLoS One}, volume = {5}, year = {2010}, month = {2010 Apr 1}, pages = {e9954}, abstract = {

Dopamine is a mediator of the stimulant properties of drugs of abuse, including ethanol, in mammals and in the fruit fly Drosophila. The neural substrates for the stimulant actions of ethanol in flies are not known. We show that a subset of dopamine neurons and their targets, through the action of the D1-like dopamine receptor DopR, promote locomotor activation in response to acute ethanol exposure. A bilateral pair of dopaminergic neurons in the fly brain mediates the enhanced locomotor activity induced by ethanol exposure, and promotes locomotion when directly activated. These neurons project to the central complex ellipsoid body, a structure implicated in regulating motor behaviors. Ellipsoid body neurons are required for ethanol-induced locomotor activity and they express DopR. Elimination of DopR blunts the locomotor activating effects of ethanol, and this behavior can be restored by selective expression of DopR in the ellipsoid body. These data tie the activity of defined dopamine neurons to D1-like DopR-expressing neurons to form a neural circuit that governs acute responding to ethanol.

}, keywords = {Animals, Behavior, Animal, Central Nervous System Depressants, Dopamine, Drosophila, Drosophila Proteins, Ethanol, Locomotion, Motor Activity, Neurons, Receptors, Dopamine}, issn = {1932-6203}, doi = {10.1371/journal.pone.0009954}, author = {Kong, Eric C and Woo, Katherine and Li, Haiyan and Lebestky, Tim and Mayer, Nasima and Sniffen, Melissa R and Heberlein, Ulrike and Bainton, Roland J and Hirsh, Jay and Wolf, Fred W} } @article {46617, title = {Protein Phosphatase 2a and glycogen synthase kinase 3 signaling modulate prepulse inhibition of the acoustic startle response by altering cortical M-Type potassium channel activity.}, journal = {The Journal of Neuroscience}, volume = {30}, year = {2010}, month = {2010 Jun 30}, pages = {8830-40}, abstract = {

There is considerable interest in the regulation of sensorimotor gating, since deficits in this process could play a critical role in the symptoms of schizophrenia and other psychiatric disorders. Sensorimotor gating is often studied in humans and rodents using the prepulse inhibition of the acoustic startle response (PPI) model, in which an acoustic prepulse suppresses behavioral output to a startle-inducing stimulus. However, the molecular and neural mechanisms underlying PPI are poorly understood. Here, we show that a regulatory pathway involving protein phosphatase 2A (PP2A), glycogen synthase kinase 3 beta (GSK3beta), and their downstream target, the M-type potassium channel, regulates PPI. Mice (Mus musculus) carrying a hypomorphic allele of Ppp2r5delta, encoding a regulatory subunit of PP2A, show attenuated PPI. This PPP2R5delta reduction increases the phosphorylation of GSK3beta at serine 9, which inactivates GSK3beta, indicating that PPP2R5delta positively regulates GSK3beta activity in the brain. Consistently, genetic and pharmacological manipulations that reduce GSK3beta function attenuate PPI. The M-type potassium channel subunit, KCNQ2, is a putative GSK3beta substrate. Genetic reduction of Kcnq2 also reduces PPI, as does systemic inhibition of M-channels with linopirdine. Importantly, both the GSK3 inhibitor 3-(2,4-dichlorophenyl)-4-(1-methyl-1H-indol-3-yl)1H-pyrrole-2,5-dione (SB216763) and linopirdine reduce PPI when directly infused into the medial prefrontal cortex (mPFC). Whole-cell electrophysiological recordings of mPFC neurons show that SB216763 and linopirdine have similar effects on firing, and GSK3 inhibition occludes the effects of M-channel inhibition. These data support a previously uncharacterized mechanism by which PP2A/GSK3beta signaling regulates M-type potassium channel activity in the mPFC to modulate sensorimotor gating.

}, keywords = {Amino Acid Sequence, Animals, Auditory Perception, Brain, Glycogen Synthase Kinase 3, Inhibition (Psychology), KCNQ2 Potassium Channel, Mice, Mice, Inbred C57BL, Mice, Transgenic, Models, Neurological, Neurons, Phosphorylation, Potassium Channels, Prefrontal Cortex, Protein Phosphatase 2, Reflex, Startle, Signal Transduction}, issn = {1529-2401}, doi = {10.1523/JNEUROSCI.1292-10.2010}, author = {Kapfhamer, David and Berger, Karen H and Hopf, F Woodward and Seif, Taban and Kharazia, Viktor and Bonci, Antonello and Heberlein, Ulrike} } @article {46623, title = {Drosophila, a genetic model system to study cocaine-related behaviors: a review with focus on LIM-only proteins.}, journal = {Neuropharmacology}, volume = {56 Suppl 1}, year = {2009}, month = {2009}, pages = {97-106}, abstract = {

In the last decade, the fruit fly Drosophila melanogaster, highly accessible to genetic, behavioral and molecular analyses, has been introduced as a novel model organism to help decipher the complex genetic, neurochemical, and neuroanatomical underpinnings of behaviors induced by drugs of abuse. Here we review these data, focusing specifically on cocaine-related behaviors. Several of cocaine{\textquoteright}s most characteristic properties have been recapitulated in Drosophila. First, cocaine induces motor behaviors in flies that are remarkably similar to those observed in mammals. Second, repeated cocaine administration induces behavioral sensitization a form of behavioral plasticity believed to underlie certain aspects of addiction. Third, a key role for dopaminergic systems in mediating cocaine{\textquoteright}s effects has been demonstrated through both pharmacological and genetic methods. Finally, and most importantly, unbiased genetic screens, feasible because of the simplicity and scale with which flies can be manipulated in the laboratory, have identified several novel genes and pathways whose role in cocaine behaviors had not been anticipated. Many of these genes and pathways have been validated in mammalian models of drug addiction. We focus in this review on the role of LIM-only proteins in cocaine-induced behaviors.

}, keywords = {Animals, Animals, Genetically Modified, Behavior, Animal, Cocaine, Cocaine-Related Disorders, Disease Models, Animal, Dopamine Uptake Inhibitors, Drosophila melanogaster, Drosophila Proteins, Homeodomain Proteins, Models, Genetic}, issn = {0028-3908}, doi = {10.1016/j.neuropharm.2008.07.023}, author = {Heberlein, Ulrike and Tsai, Linus T-Y and Kapfhamer, David and Lasek, Amy W} } @article {46621, title = {Genetic aspects of behavioral neurotoxicology.}, journal = {Neurotoxicology}, volume = {30}, year = {2009}, month = {2009 Sep}, pages = {741-53}, abstract = {

Considerable progress has been made over the past couple of decades concerning the molecular bases of neurobehavioral function and dysfunction. The field of neurobehavioral genetics is becoming mature. Genetic factors contributing to neurologic diseases such as Alzheimer{\textquoteright}s disease have been found and evidence for genetic factors contributing to other diseases such as schizophrenia and autism are likely. This genetic approach can also benefit the field of behavioral neurotoxicology. It is clear that there is substantial heterogeneity of response with behavioral impairments resulting from neurotoxicants. Many factors contribute to differential sensitivity, but it is likely that genetic variability plays a prominent role. Important discoveries concerning genetics and behavioral neurotoxicity are being made on a broad front from work with invertebrate and piscine mutant models to classic mouse knockout models and human epidemiologic studies of polymorphisms. Discovering genetic factors of susceptibility to neurobehavioral toxicity not only helps identify those at special risk, it also advances our understanding of the mechanisms by which toxicants impair neurobehavioral function in the larger population. This symposium organized by Edward Levin and Annette Kirshner, brought together researchers from the laboratories of Michael Aschner, Douglas Ruden, Ulrike Heberlein, Edward Levin and Kathleen Welsh-Bohmer conducting studies with Caenorhabditis elegans, Drosophila, fish, rodents and humans studies to determine the role of genetic factors in susceptibility to behavioral impairment from neurotoxic exposure.

}, keywords = {Animals, Behavior, Disease Models, Animal, Genetics, Humans, Neurotoxicity Syndromes, Neurotoxins, Phylogeny, Toxicology}, issn = {1872-9711}, doi = {10.1016/j.neuro.2009.07.014}, author = {Levin, Edward D and Aschner, Michael and Heberlein, Ulrike and Ruden, Douglas and Welsh-Bohmer, Kathleen A and Bartlett, Selena and Berger, Karen and Chen, Lang and Corl, Ammon B and Eddins, Donnie and French, Rachael and Hayden, Kathleen M and Helmcke, Kirsten and Hirsch, Helmut V B and Linney, Elwood and Lnenicka, Greg and Page, Grier P and Possidente, Debra and Possidente, Bernard and Kirshner, Annette} } @article {5485, title = {Glycogen synthase kinase-3/Shaggy mediates ethanol-induced excitotoxic cell death of Drosophila olfactory neurons.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {106}, year = {2009}, month = {2009 Dec 8}, pages = {20924-9}, abstract = {

It has long been known that heavy alcohol consumption leads to neuropathology and neuronal death. While the response of neurons to an ethanol insult is strongly influenced by genetic background, the underlying mechanisms are poorly understood. Here, we show that even a single intoxicating exposure to ethanol causes non-cell-autonomous apoptotic death specifically of Drosophila olfactory neurons, which is accompanied by a loss of a behavioral response to the smell of ethanol and a blackening of the third antennal segment. The Drosophila homolog of glycogen synthase kinase-3 (GSK-3)beta, Shaggy, is required for ethanol-induced apoptosis. Consistent with this requirement, the GSK-3beta inhibitor lithium protects against the neurotoxic effects of ethanol, indicating the possibility for pharmacological intervention in cases of alcohol-induced neurodegeneration. Ethanol-induced death of olfactory neurons requires both their neural activity and functional NMDA receptors. This system will allow the investigation of the genetic and molecular basis of ethanol-induced apoptosis in general and provide an understanding of the molecular role of GSK-3beta in programmed cell death.

}, keywords = {Amino Acid, Animals, Cell Death, Drosophila melanogaster, Drosophila Proteins, Electricity, Ethanol, Gene Silencing, Glycogen Synthase Kinase 3, Lithium, N-Methyl-D-Aspartate, Neurotoxins, Olfactory Receptor Neurons, Receptors, Sequence Homology, Volatilization}, issn = {1091-6490}, doi = {10.1073/pnas.0910813106}, author = {French, Rachael L and Heberlein, Ulrike} } @article {5481, title = {Happyhour, a Ste20 family kinase, implicates EGFR signaling in ethanol-induced behaviors.}, journal = {Cell}, volume = {137}, year = {2009}, month = {2009 May 29}, pages = {949-60}, abstract = {

The consequences of alcohol use disorders (AUDs) are devastating to individuals and society, yet few treatments are currently available. To identify genes regulating the behavioral effects of ethanol, we conducted a genetic screen in Drosophila and identified a mutant, happyhour (hppy), due to its increased resistance to the sedative effects of ethanol. Hppy protein shows strong homology to mammalian Ste20 family kinases of the GCK-1 subfamily. Genetic and biochemical experiments revealed that the epidermal growth factor (EGF)-signaling pathway regulates ethanol sensitivity in Drosophila and that Hppy functions as an inhibitor of the pathway. Acute pharmacological inhibition of the EGF receptor (EGFR) in adult animals altered acute ethanol sensitivity in both flies and mice and reduced ethanol consumption in a preclinical rat model of alcoholism. Inhibitors of the EGFR or components of its signaling pathway are thus potential pharmacotherapies for AUDs.

}, keywords = {Alcohol-Induced Disorders, Animal, Animals, Crosses, Disease Models, Dopamine, Drosophila melanogaster, Drosophila Proteins, Epidermal Growth Factor, Ethanol, Female, Genetic, Insulin, Male, Mice, Mutation, Phosphorylation, Protein-Serine-Threonine Kinases, Receptor, Signal Transduction}, issn = {1097-4172}, doi = {10.1016/j.cell.2009.03.020}, author = {Corl, Ammon B and Berger, Karen H and Ophir-Shohat, Galit and Gesch, Julie and Simms, Jeffrey A and Bartlett, Selena E and Heberlein, Ulrike} } @article {5486, title = {Oviposition preference for and positional avoidance of acetic acid provide a model for competing behavioral drives in Drosophila.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {106}, year = {2009}, month = {2009 Jul 7}, pages = {11352-7}, abstract = {

Selection of appropriate oviposition sites is essential for progeny survival and fitness in generalist insect species, such as Drosophila melanogaster, yet little is known about the mechanisms regulating how environmental conditions and innate adult preferences are evaluated and balanced to yield the final substrate choice for egg-deposition. Female D. melanogaster are attracted to food containing acetic acid (AA) as an oviposition substrate. However, our observations reveal that this egg-laying preference is a complex process, as it directly opposes an otherwise strong, default behavior of positional avoidance for the same food. We show that 2 distinct sensory modalities detect AA. Attraction to AA-containing food for the purpose of egg-laying relies on the gustatory system, while positional repulsion depends primarily on the olfactory system. Similarly, distinct central brain regions are involved in AA attraction and repulsion. Given this unique situation, in which a single environmental stimulus yields 2 opposing behavioral outputs, we propose that the interaction of egg-laying attraction and positional aversion for AA provides a powerful model for studying how organisms balance competing behavioral drives and integrate signals involved in choice-like processes.

}, keywords = {Acetic Acid, Animal, Animal Feed, Animals, Avoidance Learning, Biological, Brain, Drosophila melanogaster, Female, Hydrogen-Ion Concentration, Models, Neurons, Olfactory Pathways, Oviposition, Sexual Behavior, Taste}, issn = {1091-6490}, doi = {10.1073/pnas.0901419106}, author = {Joseph, Ryan M and Devineni, Anita V and King, Ian F G and Heberlein, Ulrike} } @article {4526, title = {Preferential ethanol consumption in Drosophila models features of addiction.}, journal = {Current Biology}, volume = {19}, year = {2009}, month = {2009 Dec 29}, pages = {2126-32}, abstract = {

Alcohol addiction is a common affliction with a strong genetic component [1]. Although mammalian studies have provided significant insight into the molecular mechanisms underlying ethanol consumption [2], other organisms such as Drosophila melanogaster are better suited for unbiased, forward genetic approaches to identify novel genes. Behavioral responses to ethanol, such as hyperactivity, sedation, and tolerance, are conserved between flies and mammals [3, 4], as are the underlying molecular pathways [5-9]. However, few studies have investigated ethanol self-administration in flies [10]. Here we characterize ethanol consumption and preference in Drosophila. Flies prefer to consume ethanol-containing food over regular food, and this preference increases over time. Flies are attracted to the smell of ethanol, which partially mediates ethanol preference, but are averse to its taste. Preference for consuming ethanol is not entirely explained by attraction to either its sensory or caloric properties. We demonstrate that flies can exhibit features of alcohol addiction. First, flies self-administer ethanol to pharmacologically relevant concentrations. Second, flies will overcome an aversive stimulus in order to consume ethanol. Third, flies rapidly return to high levels of ethanol consumption after a period of imposed abstinence. Thus, ethanol preference in Drosophila provides a new model for studying aspects of addiction.

}, keywords = {Alcohol Drinking, Alcoholism, Analysis of Variance, Animal, Animals, Disease Models, Drosophila melanogaster, Drosophila Proteins, Ethanol, Eukaryotic Initiation Factor-5, Food Preferences, Smell, Taste}, issn = {1879-0445}, doi = {10.1016/j.cub.2009.10.070}, author = {Devineni, Anita V and Heberlein, Ulrike} } @article {46622, title = {Sensory neurons in the Drosophila genital tract regulate female reproductive behavior.}, journal = {Neuron}, volume = {61}, year = {2009}, month = {2009 Feb 26}, pages = {511-8}, abstract = {

Females of many animal species behave very differently before and after mating. In Drosophila melanogaster, changes in female behavior upon mating are triggered by the sex peptide (SP), a small peptide present in the male{\textquoteright}s seminal fluid. SP activates a specific receptor, the sex peptide receptor (SPR), which is broadly expressed in the female reproductive tract and nervous system. Here, we pinpoint the action of SPR to a small subset of internal sensory neurons that innervate the female uterus and oviduct. These neurons express both fruitless (fru), a marker for neurons likely to have sex-specific functions, and pickpocket (ppk), a marker for proprioceptive neurons. We show that SPR expression in these fru+ ppk+ neurons is both necessary and sufficient for behavioral changes induced by mating. These neurons project to regions of the central nervous system that have been implicated in the control of reproductive behaviors in Drosophila and other insects.

}, keywords = {Animals, Drosophila, Drosophila Proteins, Female, Ganglia, Invertebrate, Gene Silencing, Genitalia, Female, Immunohistochemistry, Peptides, Sensory Receptor Cells, Sexual Behavior, Animal, Signal Transduction, Uterus}, issn = {1097-4199}, doi = {10.1016/j.neuron.2009.01.009}, author = {H{\"a}semeyer, Martin and Yapici, Nilay and Heberlein, Ulrike and Dickson, Barry J} } @article {46620, title = {Too fat to fly? New brain circuits regulate obesity in Drosophila.}, journal = {Neuron}, volume = {63}, year = {2009}, month = {2009 Aug 13}, pages = {279-81}, abstract = {

In mammals, fat store levels are regulated by brain centers that control food intake and metabolism. A new study by Al-Anzi and colleagues in this issue of Neuron identifies neurons with similar functions in Drosophila, further establishing the fly as a legitimate model to study obesity.

}, keywords = {Animals, Brain, Disease Models, Animal, Drosophila, Drosophila Proteins, Nerve Net, Neurons, Obesity}, issn = {1097-4199}, doi = {10.1016/j.neuron.2009.07.023}, author = {Kaun, Karla R and Heberlein, Ulrike} } @article {46624, title = {Ethanol sensitivity and tolerance in long-term memory mutants of Drosophila melanogaster.}, journal = {Alcoholism, Clinical and Experimental Research}, volume = {32}, year = {2008}, month = {2008 May}, pages = {895-908}, abstract = {

BACKGROUND: It has become increasingly clear that molecular and neural mechanisms underlying learning and memory and drug addiction are largely shared. To confirm and extend these findings, we analyzed ethanol-responsive behaviors of a collection of Drosophila long-term memory mutants.

METHODS: For each mutant, sensitivity to the acute uncoordinating effects of ethanol was quantified using the inebriometer. Additionally, 2 distinct forms of ethanol tolerance were measured: rapid tolerance, which develops in response to a single brief exposure to a high concentration of ethanol vapor; and chronic tolerance, which develops following a sustained low-level exposure.

RESULTS: Several mutants were identified with altered sensitivity, rapid or chronic tolerance, while a number of mutants exhibited multiple defects.

CONCLUSIONS: The corresponding genes in these mutants represent areas of potential overlap between learning and memory and behavioral responses to alcohol. These genes also define components shared between different ethanol behavioral responses.

}, keywords = {Animals, Behavior, Animal, Drosophila melanogaster, Drug Tolerance, Ethanol, Learning, Memory}, issn = {1530-0277}, doi = {10.1111/j.1530-0277.2008.00659.x}, author = {Berger, Karen H and Kong, Eric C and Dubnau, Josh and Tully, Tim and Moore, Monica S and Heberlein, Ulrike} } @article {46625, title = {Genetic dissociation of ethanol sensitivity and memory formation in Drosophila melanogaster.}, journal = {Genetics}, volume = {178}, year = {2008}, month = {2008 Apr}, pages = {1895-902}, abstract = {

The ad hoc genetic correlation between ethanol sensitivity and learning mechanisms in Drosophila could overemphasize a common process supporting both behaviors. To challenge directly the hypothesis that these mechanisms are singular, we examined the learning phenotypes of 10 new strains. Five of these have increased ethanol sensitivity, and the other 5 do not. We tested place and olfactory memory in each of these lines and found two new learning mutations. In one case, altering the tribbles gene, flies have a significantly reduced place memory, elevated olfactory memory, and normal ethanol response. In the second case, mutation of a gene we name ethanol sensitive with low memory (elm), place memory was not altered, olfactory memory was sharply reduced, and sensitivity to ethanol was increased. In sum, however, we found no overall correlation between ethanol sensitivity and place memory in the 10 lines tested. Furthermore, there was a weak but nonsignificant correlation between ethanol sensitivity and olfactory learning. Thus, mutations that alter learning and sensitivity to ethanol can occur independently of each other and this implies that the set of genes important for both ethanol sensitivity and learning is likely a subset of the genes important for either process.

}, keywords = {Animals, Behavior, Animal, Cell Cycle Proteins, DNA Transposable Elements, Drosophila melanogaster, Drosophila Proteins, Ethanol, Gene Expression Regulation, Head, Memory, Mutagenesis, Insertional, Phenotype, Protein-Serine-Threonine Kinases, RNA, Messenger}, issn = {0016-6731}, doi = {10.1534/genetics.107.084582}, author = {LaFerriere, Holly and Guarnieri, Douglas J and Sitaraman, Divya and Diegelmann, Soeren and Heberlein, Ulrike and Zars, Troy} } @article {46628, title = {GSK-3/Shaggy regulates olfactory habituation in Drosophila.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {104}, year = {2007}, month = {2007 Mar 13}, pages = {4653-7}, abstract = {

Habituation is a universal form of nonassociative learning that results in the devaluation of sensory inputs that have little information content. Although habituation is found throughout nature and has been studied in many organisms, the underlying molecular mechanisms remain poorly understood. We performed a forward genetic screen in Drosophila to search for mutations that modified habituation of an olfactory-mediated locomotor startle response, and we isolated a mutation in the glycogen synthase kinase-3 (GSK-3) homolog Shaggy. Decreases in Shaggy levels blunted habituation, whereas increases promoted habituation. Additionally, habituation acutely regulated Shaggy by an inhibitory phosphorylation mechanism, suggesting that a signal transduction pathway that regulates Shaggy is engaged during habituation. Although shaggy mutations also affected circadian rhythm period, this requirement was genetically separable from its role in habituation. Thus, shaggy functions in different neuronal circuits to regulate behavioral plasticity to an olfactory startle and circadian rhythmicity.

}, keywords = {Alleles, Animals, Behavior, Animal, Circadian Rhythm, Drosophila, Drosophila Proteins, Female, Glycogen Synthase Kinase 3, Habituation, Psychophysiologic, Male, Models, Genetic, Mutation, Phosphorylation, Signal Transduction, Smell}, issn = {0027-8424}, doi = {10.1073/pnas.0700493104}, author = {Wolf, Fred W and Eddison, Mark and Lee, Seonok and Cho, William and Heberlein, Ulrike} } @article {46630, title = {Guidelines on nicotine dose selection for in vivo research.}, journal = {Psychopharmacology (Berl)}, volume = {190}, year = {2007}, month = {2007 Feb}, pages = {269-319}, abstract = {

RATIONALE: This review provides insight for the judicious selection of nicotine dose ranges and routes of administration for in vivo studies. The literature is replete with reports in which a dosaging regimen chosen for a specific nicotine-mediated response was suboptimal for the species used. In many cases, such discrepancies could be attributed to the complex variables comprising species-specific in vivo responses to acute or chronic nicotine exposure.

OBJECTIVES: This review capitalizes on the authors{\textquoteright} collective decades of in vivo nicotine experimentation to clarify the issues and to identify the variables to be considered in choosing a dosaging regimen. Nicotine dose ranges tolerated by humans and their animal models provide guidelines for experiments intended to extrapolate to human tobacco exposure through cigarette smoking or nicotine replacement therapies. Just as important are the nicotine dosaging regimens used to provide a mechanistic framework for acquisition of drug-taking behavior, dependence, tolerance, or withdrawal in animal models.

RESULTS: Seven species are addressed: humans, nonhuman primates, rats, mice, Drosophila, Caenorhabditis elegans, and zebrafish. After an overview on nicotine metabolism, each section focuses on an individual species, addressing issues related to genetic background, age, acute vs chronic exposure, route of administration, and behavioral responses.

CONCLUSIONS: The selected examples of successful dosaging ranges are provided, while emphasizing the necessity of empirically determined dose-response relationships based on the precise parameters and conditions inherent to a specific hypothesis. This review provides a new, experimentally based compilation of species-specific dose selection for studies on the in vivo effects of nicotine.

}, keywords = {Animals, Behavioral Research, Dose-Response Relationship, Drug, Ganglionic Stimulants, Guidelines as Topic, Humans, Models, Biological, Nicotine, Species Specificity}, issn = {0033-3158}, doi = {10.1007/s00213-006-0441-0}, author = {Matta, Shannon G and Balfour, David J and Benowitz, Neal L and Boyd, R Thomas and Buccafusco, Jerry J and Caggiula, Anthony R and Craig, Caroline R and Collins, Allan C and Damaj, M Imad and Donny, Eric C and Gardiner, Phillip S and Grady, Sharon R and Heberlein, Ulrike and Leonard, Sherry S and Levin, Edward D and Lukas, Ronald J and Markou, Athina and Marks, Michael J and McCallum, Sarah E and Parameswaran, Neeraja and Perkins, Kenneth A and Picciotto, Marina R and Quik, Maryka and Rose, Jed E and Rothenfluh, Adrian and Schafer, William R and Stolerman, Ian P and Tyndale, Rachel F and Wehner, Jeanne M and Zirger, Jeffrey M} } @article {5487, title = {Distinct behavioral responses to ethanol are regulated by alternate RhoGAP18B isoforms.}, journal = {Cell}, volume = {127}, year = {2006}, month = {2006 Oct 6}, pages = {199-211}, abstract = {

In most organisms, low ethanol doses induce increased activity, while high doses are sedating. To investigate the underlying mechanisms, we isolated Drosophila mutants with altered ethanol responsiveness. Mutations in white rabbit (whir), disrupting RhoGAP18B, are strongly resistant to the sedating effects of ethanol. This resistance can be suppressed by reducing the levels of Rho1 or Rac, implicating these GTPases in the behavioral response to ethanol. Indeed, expression of constitutively active forms of Rho1 or Rac1 in adult flies results in ethanol resistance similar to that observed in whir mutants. The whir locus produces several transcripts, RA-RD, which are predicted to encode three distinct RhoGAPs that share only the GAP domain. The RC transcript mediates the sedating effects of ethanol, while the RA transcript regulates its stimulant effects. Thus, distinct RhoGAPs, encoded by the same gene, regulate different manifestations of acute ethanol intoxication.

}, keywords = {Animal, Animals, Behavior, Brain, Central Nervous System Depressants, Drosophila melanogaster, Drosophila Proteins, Enzyme Activation, Ethanol, Female, GTPase-Activating Proteins, Humans, Molecular Sequence Data, Motor Activity, Mutation, Protein Isoforms, Rabbits, rho GTP-Binding Proteins, Transgenes}, issn = {0092-8674}, doi = {10.1016/j.cell.2006.09.010}, author = {Rothenfluh, Adrian and Threlkeld, Robert J and Bainton, Roland J and Tsai, Linus T-Y and Lasek, Amy W and Heberlein, Ulrike} } @article {46629, title = {Increased ethanol resistance and consumption in Eps8 knockout mice correlates with altered actin dynamics.}, journal = {Cell}, volume = {127}, year = {2006}, month = {2006 Oct 6}, pages = {213-26}, abstract = {

Dynamic modulation of the actin cytoskeleton is critical for synaptic plasticity, abnormalities of which are thought to contribute to mental illness and addiction. Here we report that mice lacking Eps8, a regulator of actin dynamics, are resistant to some acute intoxicating effects of ethanol and show increased ethanol consumption. In the brain, the N-methyl-D-aspartate (NMDA) receptor is a major target of ethanol. We show that Eps8 is localized to postsynaptic structures and is part of the NMDA receptor complex. Moreover, in Eps8 null mice, NMDA receptor currents and their sensitivity to inhibition by ethanol are abnormal. In addition, Eps8 null neurons are resistant to the actin-remodeling activities of NMDA and ethanol. We propose that proper regulation of the actin cytoskeleton is a key determinant of cellular and behavioral responses to ethanol.

}, keywords = {Actins, Adaptor Proteins, Signal Transducing, Alcohol Drinking, Animals, Behavior, Animal, Cells, Cultured, Central Nervous System Depressants, Cerebellum, Cytoskeletal Proteins, Cytoskeleton, Ethanol, Female, Humans, Male, Mice, Mice, Knockout, Neurons, Receptors, N-Methyl-D-Aspartate, Recombinant Proteins, Signal Transduction}, issn = {0092-8674}, doi = {10.1016/j.cell.2006.09.011}, author = {Offenh{\"a}user, Nina and Castelletti, Daniela and Mapelli, Lisa and Soppo, Blanche Ekalle and Regondi, Maria Cristina and Rossi, Paola and D{\textquoteright}Angelo, Egidio and Frassoni, Carolina and Amadeo, Alida and Tocchetti, Arianna and Pozzi, Benedetta and Disanza, Andrea and Guarnieri, Douglas and Betsholtz, Christer and Scita, Giorgio and Heberlein, Ulrike and Di Fiore, Pier Paolo} } @article {46631, title = {GPCR signaling is required for blood-brain barrier formation in drosophila.}, journal = {Cell}, volume = {123}, year = {2005}, month = {2005 Oct 7}, pages = {133-44}, abstract = {

The blood-brain barrier of Drosophila is established by surface glia, which ensheath the nerve cord and insulate it against the potassium-rich hemolymph by forming intercellular septate junctions. The mechanisms underlying the formation of this barrier remain obscure. Here, we show that the G protein-coupled receptor (GPCR) Moody, the G protein subunits G alpha i and G alpha o, and the regulator of G protein signaling Loco are required in the surface glia to achieve effective insulation. Our data suggest that the four proteins act in a complex common pathway. At the cellular level, the components function by regulating the cortical actin and thereby stabilizing the extended morphology of the surface glia, which in turn is necessary for the formation of septate junctions of sufficient length to achieve proper sealing of the nerve cord. Our study demonstrates the importance of morphogenetic regulation in blood-brain barrier development and places GPCR signaling at its core.

}, keywords = {Actins, Alternative Splicing, Animals, Blood-Brain Barrier, Brain, Drosophila melanogaster, Drosophila Proteins, Endothelium, Vascular, GTP-Binding Protein alpha Subunits, Gi-Go, Microscopy, Electron, Transmission, Nerve Tissue Proteins, Neuroglia, Receptors, G-Protein-Coupled, Signal Transduction, Tight Junctions}, issn = {0092-8674}, doi = {10.1016/j.cell.2005.08.037}, author = {Schwabe, Tina and Bainton, Roland J and Fetter, Richard D and Heberlein, Ulrike and Gaul, Ulrike} } @article {5489, title = {The hangover gene defines a stress pathway required for ethanol tolerance development.}, journal = {Nature}, volume = {436}, year = {2005}, month = {2005 Aug 11}, pages = {845-7}, abstract = {

Repeated alcohol consumption leads to the development of tolerance, simply defined as an acquired resistance to the physiological and behavioural effects of the drug. This tolerance allows increased alcohol consumption, which over time leads to physical dependence and possibly addiction. Previous studies have shown that Drosophila develop ethanol tolerance, with kinetics of acquisition and dissipation that mimic those seen in mammals. This tolerance requires the catecholamine octopamine, the functional analogue of mammalian noradrenaline. Here we describe a new gene, hangover, which is required for normal development of ethanol tolerance. hangover flies are also defective in responses to environmental stressors, such as heat and the free-radical-generating agent paraquat. Using genetic epistasis tests, we show that ethanol tolerance in Drosophila relies on two distinct molecular pathways: a cellular stress pathway defined by hangover, and a parallel pathway requiring octopamine. hangover encodes a large nuclear zinc-finger protein, suggesting a role in nucleic acid binding. There is growing recognition that stress, at both the cellular and systemic levels, contributes to drug- and addiction-related behaviours in mammals. Our studies suggest that this role may be conserved across evolution.

}, keywords = {Alcoholism, Animals, Drosophila melanogaster, Drosophila Proteins, Drug Tolerance, Ethanol, Heat-Shock Response, Mutation, Physiological, Stress, Zinc Fingers}, issn = {1476-4687}, doi = {10.1038/nature03864}, author = {Scholz, Henrike and Franz, Mirjam and Heberlein, Ulrike} } @article {5490, title = {Insulin signaling in the nervous system regulates ethanol intoxication in Drosophila melanogaster.}, journal = {Nature Neuroscience}, volume = {8}, year = {2005}, month = {2005 Jan}, pages = {18-9}, abstract = {

The insulin signaling pathway regulates multiple physiological processes, including energy metabolism, organismal growth, aging and reproduction. Here we show that genetic manipulations in Drosophila melanogaster that impair the function of insulin-producing cells or of the insulin-receptor signaling pathway in the nervous system lead to increased sensitivity to the intoxicating effects of ethanol. These findings suggest a previously unknown role for this highly conserved pathway in regulating the behavioral responses to an addictive drug.

}, keywords = {Alcoholic Intoxication, Animals, Brain, Drosophila melanogaster, Ethanol, Insulin, Neurons, Receptor, Signal Transduction}, issn = {1097-6256}, doi = {10.1038/nn1363}, author = {Corl, Ammon B and Rodan, Aylin R and Heberlein, Ulrike} } @article {5488, title = {Moody encodes two GPCRs that regulate cocaine behaviors and blood-brain barrier permeability in Drosophila.}, journal = {Cell}, volume = {123}, year = {2005}, month = {2005 Oct 7}, pages = {145-56}, abstract = {

We identified moody in a genetic screen for Drosophila mutants with altered cocaine sensitivity. Hypomorphic mutations in moody cause an increased sensitivity to cocaine and nicotine exposure. In contrast, sensitivity to the acute intoxicating effects of ethanol is reduced. The moody locus encodes two novel GPCRs, Moody-alpha and Moody-beta. While identical in their membrane-spanning domains, the two Moody proteins differ in their long carboxy-terminal domains, which are generated by use of alternative reading frames. Both Moody forms are required for normal cocaine sensitivity, suggesting that they carry out distinct but complementary functions. Moody-alpha and Moody-beta are coexpressed in surface glia that surround the nervous system, where they are actively required to maintain the integrity of the blood-brain barrier in the adult fly. We propose that a Moody-mediated signaling pathway functions in glia to regulate nervous system insulation and drug-related behaviors.

}, keywords = {Alternative Splicing, Animal, Animals, Behavior, Blood-Brain Barrier, Brain, Cocaine, Cocaine-Related Disorders, Disease Models, Dopamine Uptake Inhibitors, Drosophila melanogaster, Drosophila Proteins, Drug Tolerance, G-Protein-Coupled, Male, Motor Activity, Neuroglia, Nicotine, Protein Structure, Receptors, Substance-Related Disorders, Tertiary}, issn = {0092-8674}, doi = {10.1016/j.cell.2005.07.029}, author = {Bainton, Roland J and Tsai, Linus T-Y and Schwabe, Tina and DeSalvo, Michael and Gaul, Ulrike and Heberlein, Ulrike} } @article {5491, title = {Lmo mutants reveal a novel role for circadian pacemaker neurons in cocaine-induced behaviors.}, journal = {PLoS Biology}, volume = {2}, year = {2004}, month = {2004 Dec}, pages = {e408}, abstract = {

Drosophila has been developed recently as a model system to investigate the molecular and neural mechanisms underlying responses to drugs of abuse. Genetic screens for mutants with altered drug-induced behaviors thus provide an unbiased approach to define novel molecules involved in the process. We identified mutations in the Drosophila LIM-only (LMO) gene, encoding a regulator of LIM-homeodomain proteins, in a genetic screen for mutants with altered cocaine sensitivity. Reduced Lmo function increases behavioral responses to cocaine, while Lmo overexpression causes the opposite effect, reduced cocaine responsiveness. Expression of Lmo in the principal Drosophila circadian pacemaker cells, the PDF-expressing ventral lateral neurons (LN(v)s), is sufficient to confer normal cocaine sensitivity. Consistent with a role for Lmo in LN(v)function,Lmomutants also show defects in circadian rhythms of behavior. However, the role for LN(v)s in modulating cocaine responses is separable from their role as pacemaker neurons: ablation or functional silencing of the LN(v)s reduces cocaine sensitivity, while loss of the principal circadian neurotransmitter PDF has no effect. Together, these results reveal a novel role for Lmo in modulating acute cocaine sensitivity and circadian locomotor rhythmicity, and add to growing evidence that these behaviors are regulated by shared molecular mechanisms. The finding that the degree of cocaine responsiveness is controlled by the Drosophila pacemaker neurons provides a neuroanatomical basis for this overlap. We propose that Lmo controls the responsiveness of LN(v)s to cocaine, which in turn regulate the flies{\textquoteright} behavioral sensitivity to the drug.

}, keywords = {Alleles, Animal, Animals, Behavior, Biological, Biological Clocks, Circadian Rhythm, Cocaine, Drosophila melanogaster, Drosophila Proteins, Gene Expression Regulation, Gene Silencing, Genetic, Homeodomain Proteins, Models, Mutation, Neurons, Neuropeptides, Neurotransmitter Agents, Protein Structure, Reverse Transcriptase Polymerase Chain Reaction, Tertiary}, issn = {1545-7885}, doi = {10.1371/journal.pbio.0020408}, author = {Tsai, Linus T-Y and Bainton, Roland J and Blau, Justin and Heberlein, Ulrike} } @article {46633, title = {Molecular Genetic Analysis of Ethanol Intoxication in Drosophila melanogaster.}, journal = {Integrative and Comparative Biology}, volume = {44}, year = {2004}, month = {2004 Aug}, pages = {269-74}, abstract = {

Recently, the fruit fly Drosophila melanogaster has been introduced as a model system to study the molecular bases of a variety of ethanol-induced behaviors. It became immediately apparent that the behavioral changes elicited by acute ethanol exposure are remarkably similar in flies and mammals. Flies show signs of acute intoxication, which range from locomotor stimulation at low doses to complete sedation at higher doses and they develop tolerance upon intermittent ethanol exposure. Genetic screens for mutants with altered responsiveness to ethanol have been carried out and a few of the disrupted genes have been identified. This analysis, while still in its early stages, has already revealed some surprising molecular parallels with mammals. The availability of powerful tools for genetic manipulation in Drosophila, together with the high degree of conservation at the genomic level, make Drosophila a promising model organism to study the mechanism by which ethanol regulates behavior and the mechanisms underlying the organism{\textquoteright}s adaptation to long-term ethanol exposure.

}, issn = {1540-7063}, doi = {10.1093/icb/44.4.269}, author = {Heberlein, Ulrike and Wolf, Fred W and Rothenfluh, Adrian and Guarnieri, Douglas J} } @article {46632, title = {Rapid and chronic: two distinct forms of ethanol tolerance in Drosophila.}, journal = {Alcoholism, Clinical and Experimental Research}, volume = {28}, year = {2004}, month = {2004 Oct}, pages = {1469-80}, abstract = {

BACKGROUND: Ethanol tolerance, defined as a reduction in the intensity of the effects of ethanol upon continuous or repeated exposure, is a hallmark of alcoholism. Tolerance may develop at the cellular or neural systems levels. The molecular changes underlying ethanol tolerance are not well understood. We therefore explored the utility of Drosophila, with its accessibility to genetic, molecular, and behavioral analyses, as a model organism to study tolerance development in response to different ethanol-exposure regimens.

METHODS: We describe a new assay that quantifies recovery from ethanol intoxication in Drosophila. Using this recovery assay, we define ethanol pre-exposure paradigms that lead to the development of tolerance. We also use the inebriometer, an assay that measures the onset of intoxication, to study the effects of pharmacological and genetic manipulations on tolerance development.

RESULTS: We show that flies develop different forms of ethanol tolerance: rapid tolerance, induced by a single short exposure to a high concentration of ethanol, and chronic tolerance, elicited by prolonged exposure to a low concentration of the drug. Neither rapid nor chronic tolerance involves changes in ethanol pharmacokinetics, implying that they represent functional rather than dispositional tolerance. Chronic and rapid tolerance can be distinguished mechanistically: chronic tolerance is disrupted by treatment with the protein synthesis inhibitor cycloheximide, whereas rapid tolerance is resistant to this treatment. Furthermore, rapid and chronic tolerance rely on distinct genetic pathways: a mutant defective for octopamine biosynthesis shows reduced rapid tolerance but normal chronic tolerance.

CONCLUSIONS: Flies, like mammals, develop tolerance in response to different ethanol-exposure regimens, and this tolerance affects both the onset of and the recovery from acute intoxication. Two forms of tolerance, rapid and chronic, are mechanistically distinct, because they can be dissociated genetically and pharmacologically.

}, keywords = {Animals, Drosophila, Drug Tolerance, Ethanol, Male, Models, Animal, Time Factors}, issn = {0145-6008}, author = {Berger, Karen H and Heberlein, Ulrike and Moore, Monica S} } @article {46636, title = {Drosophila melanogaster, a genetic model system for alcohol research.}, journal = {International Review of Neurobiology}, volume = {54}, year = {2003}, month = {2003}, pages = {199-228}, abstract = {

In its natural environment, which consists of fermenting plant materials, the fruit fly Drosophila melanogaster encounters high levels of ethanol. Flies are well equipped to deal with the toxic effects of ethanol; they use it as an energy source and for lipid biosynthesis. The primary ethanol-metabolizing pathway in flies involves the enzymes alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH); their role in adaptation to ethanol-rich environments has been studied extensively. The similarity between Drosophila and mammals is not restricted to the manner in which they metabolize ethanol; behaviors elicited by ethanol exposure are also remarkably similar in these organisms. Flies show signs of acute intoxication, which range from locomotor stimulation at low doses to complete sedation at higher doses, they develop tolerance upon intermittent ethanol exposure, and they appear to like ethanol, showing preference for ethanol-containing media. Molecular genetic analysis of ethanol-induced behaviors in Drosophila, while still in its early stages, has already revealed some surprising parallels with mammals. The availability of powerful tools for genetic manipulation in Drosophila, together with the high degree of conservation at the genomic level, make Drosophila a promising model organism to study the mechanism by which ethanol regulates behavior and the mechanisms underlying the organism{\textquoteright}s adaptation to long-term ethanol exposure.

}, keywords = {Alcohol Dehydrogenase, Alcoholism, Aldehyde Oxidoreductases, Animals, Behavior, Animal, Cell Membrane, Conditioning (Psychology), Drosophila melanogaster, Drug Tolerance, Ethanol, Humans, Models, Animal, Mutation}, issn = {0074-7742}, author = {Guarnieri, Douglas J and Heberlein, Ulrike} } @article {46639, title = {Invertebrate models of drug abuse.}, journal = {Journal of Neurobiology}, volume = {54}, year = {2003}, month = {2003 Jan}, pages = {161-78}, abstract = {

Susceptibility to drug addiction depends on genetic and environmental factors and their complex interactions. Studies with mammalian models have identified molecular targets, neurochemical systems, and brain regions that mediate some of the addictive properties of abused drugs. Yet, our understanding of how the primary effects of drugs lead to addiction remains incomplete. Recently, researchers have turned to the invertebrate model systems Drosophila melanogaster and Caenorhabditis elegans to dissect the mechanisms by which abused drugs modulate behavior. Due to their sophisticated genetics, relatively simple anatomy, and their remarkable molecular similarity to mammals, these invertebrate models should provide useful insights into the mechanisms of drug action. Here we review recent behavioral and genetic studies in flies and worms on the effects of ethanol, cocaine, and nicotine, three of the most widely abused drugs in the world.

}, keywords = {Alcoholic Intoxication, Animals, Behavior, Animal, Caenorhabditis elegans, Cocaine, Disease Models, Animal, Dopamine, Drosophila melanogaster, Drug Tolerance, Ethanol, Learning, Memory, Nicotine, Substance-Related Disorders}, issn = {0022-3034}, doi = {10.1002/neu.10166}, author = {Wolf, Fred W and Heberlein, Ulrike} } @article {46637, title = {Mechanism of hedgehog signaling during Drosophila eye development.}, journal = {Development}, volume = {130}, year = {2003}, month = {2003 Jul}, pages = {3053-62}, abstract = {

Although Hedgehog (Hh) signaling is essential for morphogenesis of the Drosophila eye, its exact link to the network of tissue-specific genes that regulate retinal determination has remained elusive. In this report, we demonstrate that the retinal determination gene eyes absent (eya) is the crucial link between the Hedgehog signaling pathway and photoreceptor differentiation. Specifically, we show that the mechanism by which Hh signaling controls initiation of photoreceptor differentiation is to alleviate repression of eya and decapentaplegic (dpp) expression by the zinc-finger transcription factor Cubitus interruptus (Ci(rep)). Furthermore, our results suggest that stabilized, full length Ci (Ci(act)) plays little or no role in Drosophila eye development. Moreover, while the effects of Hh are primarily concentration dependent in other tissues, hh signaling in the eye acts as a binary switch to initiate retinal morphogenesis by inducing expression of the tissue-specific factor Eya.

}, keywords = {Animals, Cell Differentiation, DNA-Binding Proteins, Drosophila melanogaster, Drosophila Proteins, Eye Proteins, Hedgehog Proteins, Models, Biological, Morphogenesis, Organisms, Genetically Modified, Photoreceptor Cells, Invertebrate, Signal Transduction, Transcription Factors, Wing}, issn = {0950-1991}, author = {Pappu, Kartik S and Chen, Rui and Middlebrooks, Brooke W and Woo, Catherine and Heberlein, Ulrike and Mardon, Graeme} } @article {46635, title = {Tre1, a G protein-coupled receptor, directs transepithelial migration of Drosophila germ cells.}, journal = {PLoS Biology}, volume = {1}, year = {2003}, month = {2003 Dec}, pages = {E80}, abstract = {

In most organisms, germ cells are formed distant from the somatic part of the gonad and thus have to migrate along and through a variety of tissues to reach the gonad. Transepithelial migration through the posterior midgut (PMG) is the first active step during Drosophila germ cell migration. Here we report the identification of a novel G protein-coupled receptor (GPCR), Tre1, that is essential for this migration step. Maternal tre1 RNA is localized to germ cells, and tre1 is required cell autonomously in germ cells. In tre1 mutant embryos, most germ cells do not exit the PMG. The few germ cells that do leave the midgut early migrate normally to the gonad, suggesting that this gene is specifically required for transepithelial migration and that mutant germ cells are still able to recognize other guidance cues. Additionally, inhibiting small Rho GTPases in germ cells affects transepithelial migration, suggesting that Tre1 signals through Rho1. We propose that Tre1 acts in a manner similar to chemokine receptors required during transepithelial migration of leukocytes, implying an evolutionarily conserved mechanism of transepithelial migration. Recently, the chemokine receptor CXCR4 was shown to direct migration in vertebrate germ cells. Thus, germ cells may more generally use GPCR signaling to navigate the embryo toward their target.

}, keywords = {Animals, Cell Movement, Cell Transplantation, Cloning, Molecular, Crosses, Genetic, Drosophila melanogaster, Drosophila Proteins, Embryo, Nonmammalian, Epithelium, Evolution, Molecular, Female, Gene Expression Regulation, Germ Cells, Humans, Immunohistochemistry, In Situ Hybridization, Inflammation, Leukocytes, Male, Models, Biological, Molecular Sequence Data, Mutation, Phenotype, Phylogeny, Receptors, Chemokine, Receptors, G-Protein-Coupled, rho GTP-Binding Proteins, RNA, Signal Transduction}, issn = {1545-7885}, doi = {10.1371/journal.pbio.0000080}, author = {Kunwar, Prabhat S and Starz-Gaiano, Michelle and Bainton, Roland J and Heberlein, Ulrike and Lehmann, Ruth} } @article {46638, title = {Drugs, flies, and videotape: the effects of ethanol and cocaine on Drosophila locomotion.}, journal = {Current Opinion in Neurobiology}, volume = {12}, year = {2002}, month = {2002 Dec}, pages = {639-45}, abstract = {

Drosophila melanogaster has been introduced recently as a model organism in which to study the mechanisms by which drugs of abuse change behavior and by which the nervous system changes upon repeated drug exposure. Surprising similarities between flies and mammals have begun to emerge at the behavioral, neurochemical and molecular levels.

}, keywords = {Animals, Behavior, Animal, Circadian Rhythm, Cocaine, Cyclic AMP, Dopamine, Drosophila melanogaster, Drug Tolerance, Ethanol, Locomotion}, issn = {0959-4388}, author = {Rothenfluh, Adrian and Heberlein, Ulrike} } @article {5493, title = {Functional dissection of neuroanatomical loci regulating ethanol sensitivity in Drosophila.}, journal = {The Journal of Neuroscience: The Official Journal of the Society for Neuroscience}, volume = {22}, year = {2002}, month = {2002 Nov 1}, pages = {9490-501}, abstract = {

Ethanol has complex but similar effects on behavior in mammals and the fruit fly Drosophila melanogaster. In addition, genetic and pharmacological approaches have implicated the cAMP pathway in the regulation of ethanol-induced behaviors in both flies and rodents. Here we examine the neuroanatomical loci that modulate ethanol sensitivity in Drosophila by targeting the expression of an inhibitor of cAMP-dependent protein kinase (PKA) to specific regions in the fly{\textquoteright}s brain. Expression of the inhibitor in most brain regions or in muscle has no effect on behavior. In contrast, inhibition of PKA in a relatively small number of cells, possibly neurosecretory cells, in the fly{\textquoteright}s brain is sufficient to decrease sensitivity to the incoordinating effects of ethanol. Additional brain areas are, however, also involved. The mushroom bodies, brain structures where cAMP signaling is required for olfactory classical conditioning, are dispensable for the regulation of ethanol sensitivity. Finally, different behavioral effects of ethanol, motor incoordination and sedation, appear to be regulated by PKA function in distinct brain regions. We conclude that the regulation of ethanol-induced behaviors by PKA involves complex interactions among groups of cells that mediate either increased or reduced sensitivity to the acute intoxicating effects of ethanol.

}, keywords = {Administration, Animal, Animals, Behavior, Catalytic Domain, Cyclic AMP-Dependent Protein Kinases, DNA-Binding Proteins, Drosophila melanogaster, Drug Resistance, Ethanol, Gene Expression, Genes, Genetically Modified, Hydroxyurea, Inhalation, Larva, Locomotion, Male, Motor Activity, Mushroom Bodies, Nervous System, Organ Specificity, Protein Subunits, Reporter, Saccharomyces cerevisiae Proteins, Transcription Factors, Transgenes}, issn = {1529-2401}, author = {Rodan, Aylin R and Kiger, John A and Heberlein, Ulrike} } @article {5492, title = {High-resolution analysis of ethanol-induced locomotor stimulation in Drosophila.}, journal = {The Journal of Neuroscience: The Official Journal of the Society for Neuroscience}, volume = {22}, year = {2002}, month = {2002 Dec 15}, pages = {11035-44}, abstract = {

Understanding how ethanol influences behavior is key to deciphering the mechanisms of ethanol action and alcoholism. In mammals, low doses of ethanol stimulate locomotion, whereas high doses depress it. The acute stimulant effect of ethanol has been proposed to be a manifestation of its rewarding effects. In Drosophila, ethanol exposure transiently potentiates locomotor activity in a biphasic dose- and time-dependent manner. An initial short-lived peak of activity corresponds to an olfactory response to ethanol. A second, longer-lasting period of increased activity coincides with rising internal ethanol concentrations; these closely parallel concentrations that stimulate locomotion in mammals. High-resolution analysis of the walking pattern of individual flies revealed that locomotion consists of bouts of activity; bout structure can be quantified by bout frequency, bout length, and the time spent walking at high speeds. Ethanol exposure induces both dramatic and dynamic changes in bout structure. Mutants with increased ethanol sensitivity show distinct changes in ethanol-induced locomotor behavior, as well as genotype-specific changes in activity bout structure. Thus, the overall effect of ethanol on locomotor behavior in Drosophila is caused by changes in discrete quantifiable parameters of walking pattern. The effects of ethanol on locomotion are comparable in flies and mammals, suggesting that Drosophila is a suitable model system to study the underlying mechanisms.

}, keywords = {Afferent Pathways, Animal, Animals, Automation, Behavior, Cyclic AMP, Dose-Response Relationship, Drosophila, Drug, Ethanol, Kinetics, Locomotion, Male, Mutation, Sensitivity and Specificity}, issn = {1529-2401}, author = {Wolf, Fred W and Rodan, Aylin R and Tsai, Linus T-Y and Heberlein, Ulrike} } @article {46640, title = {Rough eye is a gain-of-function allele of amos that disrupts regulation of the proneural gene atonal during Drosophila retinal differentiation.}, journal = {Genetics}, volume = {160}, year = {2002}, month = {2002 Feb}, pages = {623-35}, abstract = {

The regular organization of the ommatidial lattice in the Drosophila eye originates in the precise regulation of the proneural gene atonal (ato), which is responsible for the specification of the ommatidial founder cells R8. Here we show that Rough eye (Roi), a dominant mutation manifested by severe roughening of the adult eye surface, causes defects in ommatidial assembly and ommatidial spacing. The ommatidial spacing defect can be ascribed to the irregular distribution of R8 cells caused by a disruption of the patterning of ato expression. Disruptions in the recruitment of other photoreceptors and excess Hedgehog production in differentiating cells may further contribute to the defects in ommatidial assembly. Our molecular characterization of the Roi locus demonstrates that it is a gain-of-function mutation of the bHLH gene amos that results from a chromosomal inversion. We show that Roi can rescue the retinal developmental defect of ato1 mutants and speculate that amos substitutes for some of ato{\textquoteright}s function in the eye or activates a residual function of the ato1 allele.

}, keywords = {Alleles, Animals, Basic Helix-Loop-Helix Transcription Factors, DNA-Binding Proteins, Drosophila melanogaster, Drosophila Proteins, Epistasis, Genetic, Gene Expression Regulation, Developmental, Nerve Growth Factors, Nerve Tissue Proteins, Retina, Signal Transduction, Transgenes}, issn = {0016-6731}, author = {Chanut, Fran{\c c}oise and Woo, Katherine and Pereira, Shalini and Donohoe, Terrence J and Chang, Shang-Yu and Laverty, Todd R and Jarman, Andrew P and Heberlein, Ulrike} }