@article {65642, title = {Controlling motor neurons of every muscle for fly proboscis reaching.}, journal = {eLife}, volume = {9}, year = {2020}, month = {2020 Jun 25}, abstract = {

We describe the anatomy of all the primary motor neurons in the fly proboscis and characterize their contributions to its diverse reaching movements. Pairing this behavior with the wealth of genetic tools offers the possibility to study motor control at single-neuron resolution, and soon throughout entire circuits. As an entry to these circuits, we provide detailed anatomy of proboscis motor neurons, muscles, and joints. We create a collection of fly strains to individually manipulate every proboscis muscle through control of its motor neurons, the first such collection for an appendage. We generate a model of the action of each proboscis joint, and find that only a small number of motor neurons are needed to produce proboscis reaching. Comprehensive control of each motor element in this numerically simple system paves the way for future study of both reflexive and flexible movements of this appendage.

}, issn = {2050-084X}, doi = {10.7554/eLife.54978}, author = {McKellar, Claire E and Siwanowicz, Igor and Dickson, Barry J and Simpson, Julie H} } @article {65723, title = {A systematic nomenclature for the Drosophila ventral nerve cord.}, journal = {Neuron}, volume = {107}, year = {2020}, month = {2020 Sep 14}, pages = {1071-79}, abstract = {

Drosophila melanogaster is an established model for neuroscience research with relevance in biology and medicine. Until recently, research on the Drosophila brain was hindered by the lack of a complete and uniform nomenclature. Recognizing this, Ito et\ al. (2014) produced an authoritative nomenclature for the adult insect brain, using Drosophila as the reference. Here, we extend this nomenclature to the adult thoracic and abdominal neuromeres, the ventral nerve cord (VNC), to provide an anatomical description of this major component of the Drosophila nervous system. The VNC is the locus for the reception and integration of sensory information and involved in generating most of the locomotor actions that underlie fly behaviors. The aim is to create a nomenclature, definitions, and spatial boundaries for the Drosophila VNC that are consistent with other insects. The work establishes an anatomical framework that provides a powerful tool for analyzing the functional organization of the VNC.

}, issn = {1097-4199}, doi = {10.1016/j.neuron.2020.08.005}, author = {Court, Robert and Namiki, Shigehiro and Armstrong, J Douglas and Borner, Jana and Card, Gwyneth and Costa, Marta and Dickinson, Michael and Duch, Carsten and Korff, Wyatt and Mann, Richard and Merritt, David and Murphey, Rod K and Seeds, Andrew M and Shirangi, Troy and Simpson, Julie H and Truman, James W and Tuthill, John C and Williams, Darren W and Shepherd, David} } @article {56201, title = {Threshold-based ordering of sequential actions during Drosophila courtship.}, journal = {Current Biology : CB}, volume = {29}, year = {2019}, month = {2019 Jan 07}, pages = {426-34}, abstract = {

Goal-directed animal behaviors are typically composed of sequences of motor actions whose order and timing are critical for a successful outcome. Although numerous theoretical models for sequential action generation have been proposed, few have been supported by the identification of control neurons sufficient to elicit a sequence. Here, we identify a pair of descending neurons that coordinate a stereotyped sequence of engagement actions during Drosophila melanogaster male courtship behavior. These actions are initiated sequentially but persist cumulatively, a feature not explained by existing models of sequential behaviors. We find evidence consistent with a ramp-to-threshold mechanism, in which increasing neuronal activity elicits each action independently at successively higher activity thresholds.

}, issn = {1879-0445}, doi = {10.1016/j.cub.2018.12.019}, author = {McKellar, Claire E and Lillvis, Joshua L and Bath, Daniel E and Fitzgerald, James E and Cannon, John G and Simpson, Julie H and Dickson, Barry J} } @article {49142, title = {Functional Imaging and Optogenetics in Drosophila.}, journal = {Genetics}, volume = {208}, year = {2018}, month = {2018 Apr}, pages = {1291-1309}, abstract = {

Understanding how activity patterns in specific neural circuits coordinate an animal{\textquoteright}s behavior remains a key area of neuroscience research. Genetic tools and a brain of tractable complexity make a premier model organism for these studies. Here, we review the wealth of reagents available to map and manipulate neuronal activity with light.

}, issn = {1943-2631}, doi = {10.1534/genetics.117.300228}, author = {Simpson, Julie H and Looger, Loren L} } @article {48646, title = {Mapping the neural substrates of behavior.}, journal = {Cell}, volume = {170}, year = {2017}, month = {2017-07-13}, pages = {393-406}, abstract = {

Assigning behavioral functions to neural structures has long been a central goal in neuroscience and is a necessary first step toward a circuit-level understanding of how the brain generates behavior. Here, we map the neural substrates of locomotion and social behaviors for Drosophila melanogaster using automated machine-vision and machine-learning techniques. From videos of 400,000 flies, we quantified the behavioral effects of activating 2,204 genetically targeted populations of neurons. We combined a novel quantification of anatomy with our behavioral analysis to create brain-behavior correlation maps, which are shared as browsable web pages and interactive software. Based on these maps, we generated hypotheses of regions of the brain causally related to sensory processing, locomotor control, courtship, aggression, and sleep. Our maps directly specify genetic tools to target these regions, which we used to identify a small population of neurons with a role in the control of walking.

{\textbullet}We developed machine-vision methods to broadly and precisely quantify fly behavior{\textbullet}We measured effects of activating 2,204 genetically targeted neuronal populations{\textbullet}We created whole-brain maps of neural substrates of locomotor and social behaviors{\textbullet}We created resources for exploring our results and enabling further investigation

Machine-vision analyses of large behavior and neuroanatomy data reveal whole-brain maps of regions associated with numerous complex behaviors.

}, doi = {10.1016/j.cell.2017.06.032}, url = {http://dx.doi.org/10.1016/j.cell.2017.06.032}, author = {Robie, Alice A and Hirokawa, Jonathan and Edwards, Austin W and Umayam, Lowell A and Lee, Allen and Phillips, Mary L and Card, Gwyneth M and Korff, Wyatt and Rubin, Gerald M and Simpson, Julie H and Reiser, Michael B and Branson, Kristin M} } @article {48788, title = {Simultaneous activation of parallel sensory pathways promotes a grooming sequence in Drosophila.}, journal = {eLife}, volume = {6}, year = {2017}, month = {2017 Sep 09}, abstract = {

A central model that describes how behavioral sequences are produced features a neural architecture that readies different movements simultaneously, and a mechanism where prioritized suppression between the movements determines their sequential performance. We previously described a model whereby suppression drives a Drosophila grooming sequence that is induced by simultaneous activation of different sensory pathways that each elicit a distinct movement (Seeds et al. 2014). Here, we confirm this model using transgenic expression to identify and optogenetically activate sensory neurons that elicit specific grooming movements. Simultaneous activation of different sensory pathways elicits a grooming sequence that resembles the naturally induced sequence. Moreover, the sequence proceeds after the sensory excitation is terminated, indicating that a persistent trace of this excitation induces the next grooming movement once the previous one is performed. This reveals a mechanism whereby parallel sensory inputs can be integrated and stored to elicit a delayed and sequential grooming response.

}, issn = {2050-084X}, doi = {10.7554/eLife.28804}, author = {Hampel, Stefanie and McKellar, Claire E and Simpson, Julie H and Seeds, Andrew M} } @article {48657, title = {A systematic nomenclature for the Drosophila ventral nervous system.}, journal = {bioRxiv}, year = {2017}, month = {2017 Apr 26}, abstract = {

Insect nervous systems are proven and powerful model systems for neuroscience research with wide relevance in biology and medicine. However, descriptions of insect brains have suffered from a lack of a complete and uniform nomenclature. Recognising this problem the Insect Brain Name Working Group produced the first agreed hierarchical nomenclature system for the adult insect brain, using Drosophila melanogaster as the reference framework, with other insect taxa considered to ensure greater consistency and expandability (Ito et al., 2014). Ito et al. (2014) purposely focused on the gnathal regions that account for approximately 50\% of the adult CNS. We extend this nomenclature system to the sub-gnathal regions of the adult Drosophila nervous system to provide a nomenclature of the so-called ventral nervous system (VNS), which includes the thoracic and abdominal neuromeres that was not included in the original work and contains the neurons that play critical roles underpinning most fly behaviours.

}, doi = {10.1101/122952}, author = {Court, Robert Christopher and Armstrong, James Douglas and Borner, Jana and Card, Gwyneth M and Costa, Marta and Dickinson, Michael H and Duch, Carsten and Korff, Wyatt and Mann, Richard S and Merritt, David and Murphey, Rodney K and Namiki, Shigehiro and Seeds, Andrew M and Shepherd, David and Shirangi, Troy R and Simpson, Julie H and Truman, James W and Tuthill, John C and Williams, Darren W} } @article {46549, title = {Generating customized transgene landing sites and multi-transgene arrays in Drosophila using phiC31 integrase.}, journal = {Genetics}, volume = {199}, year = {2015}, month = {2015 Apr}, pages = {919-34}, abstract = {

Transgenesis in numerous eukaryotes has been facilitated by the use of site-specific integrases to stably insert transgenes at predefined genomic positions (landing sites). However, the utility of integrase-mediated transgenesis in any system is constrained by the limited number and variable expression properties of available landing sites. By exploiting the nonstandard recombination activity exhibited by a phiC31 integrase mutant, we developed a rapid and inexpensive method for isolating landing sites that exhibit desired expression properties. Additionally, we devised a simple technique for constructing arrays of transgenes at a single landing site, thereby extending the utility of previously characterized landing sites. Using the fruit fly Drosophila melanogaster, we demonstrate the feasibility of these approaches by isolating new landing sites optimized to express transgenes in the nervous system and by building fluorescent reporter arrays at several landing sites. Because these strategies require the activity of only a single exogenous protein, we anticipate that they will be portable to species such as nonmodel organisms, in which genetic manipulation is more challenging, expediting the development of genetic resources in these systems.

}, issn = {1943-2631}, doi = {10.1534/genetics.114.173187}, author = {Knapp, Jon-Michael and Chung, Phuong and Simpson, Julie H} } @article {47038, title = {A neural command circuit for grooming movement control.}, journal = {eLife}, volume = {4}, year = {2015}, month = {2015 Sep 7}, abstract = {

Animals perform many stereotyped movements, but how nervous systems are organized for controlling specific movements remains unclear. Here we use anatomical, optogenetic, behavioral, and physiological techniques to identify a circuit in Drosophila melanogaster that can elicit stereotyped leg movements that groom the antennae. Mechanosensory chordotonal neurons detect displacements of the antennae and excite three different classes of functionally connected interneurons, which include two classes of brain interneurons and different parallel descending neurons. This multilayered circuit is organized such that neurons within each layer are sufficient to specifically elicit antennal grooming. However, we find differences in the durations of antennal grooming elicited by neurons in the different layers, suggesting that the circuit is organized to both command antennal grooming and control its duration. As similar features underlie stimulus-induced movements in other animals, we infer the possibility of a common circuit organization for movement control that can be dissected in Drosophila.

}, issn = {2050-084X}, doi = {10.7554/eLife.08758}, author = {Hampel, Stefanie and Franconville, Romain and Simpson, Julie H and Seeds, Andrew M} } @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 {45696, title = {A genetically specified connectomics approach applied to long-range feeding regulatory circuits.}, journal = {Nature Neuroscience}, volume = {17}, year = {2014}, month = {2014 Dec}, pages = {1830-9}, abstract = {

Synaptic connectivity and molecular composition provide a blueprint for information processing in neural circuits. Detailed structural analysis of neural circuits requires nanometer resolution, which can be obtained with serial-section electron microscopy. However, this technique remains challenging for reconstructing molecularly defined synapses. We used a genetically encoded synaptic marker for electron microscopy (GESEM) based on intra-vesicular generation of electron-dense labeling in axonal boutons. This approach allowed the identification of synapses from Cre recombinase-expressing or GAL4-expressing neurons in the mouse and fly with excellent preservation of ultrastructure. We applied this tool to visualize long-range connectivity of AGRP and POMC neurons in the mouse, two molecularly defined hypothalamic populations that are important for feeding behavior. Combining selective ultrastructural reconstruction of neuropil with functional and viral circuit mapping, we characterized some basic features of circuit organization for axon projections of these cell types. Our findings demonstrate that GESEM labeling enables long-range connectomics with molecularly defined cell types.

}, issn = {1546-1726}, doi = {10.1038/nn.3854}, author = {Atasoy, Deniz and Betley, J Nicholas and Li, Wei-Ping and Su, Helen H and Sertel, Sinem M and Scheffer, Louis K and Simpson, Julie H and Fetter, Richard D and Sternson, Scott M} } @article {45417, title = {A suppression hierarchy among competing motor programs drives sequential grooming in Drosophila.}, journal = {eLife}, volume = {3}, year = {2014}, month = {2014 Aug 19}, pages = {e02951}, abstract = {

Motor sequences are formed through the serial execution of different movements, but how nervous systems implement this process remains largely unknown. We determined the organizational principles governing how dirty fruit flies groom their bodies with sequential movements. Using genetically targeted activation of neural subsets, we drove distinct motor programs that clean individual body parts. This enabled competition experiments revealing that the motor programs are organized into a suppression hierarchy; motor programs that occur first suppress those that occur later. Cleaning one body part reduces the sensory drive to its motor program, which relieves suppression of the next movement, allowing the grooming sequence to progress down the hierarchy. A model featuring independently evoked cleaning movements activated in parallel, but selected serially through hierarchical suppression, was successful in reproducing the grooming sequence. This provides the first example of an innate motor sequence implemented by the prevailing model for generating human action sequences.

}, issn = {2050-084X}, doi = {10.7554/eLife.02951}, author = {Seeds, Andrew M and Ravbar, Primoz and Chung, Phuong and Hampel, Stefanie and Midgley, Frank M and Mensh, Brett D and Simpson, Julie H} } @article {6884, title = {A systematic nomenclature for the insect brain.}, journal = {Neuron}, volume = {81}, year = {2014}, month = {2014 Feb 19}, pages = {755-65}, abstract = {

Despite the importance of the insect nervous system for functional and developmental neuroscience, descriptions of insect brains have suffered from a lack of uniform nomenclature. Ambiguous definitions of brain regions and fiber bundles have contributed to the variation of names used to describe the same structure. The lack of clearly determined neuropil boundaries has made it difficult to document precise locations of neuronal projections for connectomics study. To address such issues, a consortium of\ neurobiologists studying arthropod brains, the Insect Brain Name Working Group, has established the present hierarchical nomenclature system, using the brain of Drosophila melanogaster as the reference framework, while taking the brains of other taxa into careful consideration for maximum consistency and expandability. The following summarizes the consortium{\textquoteright}s nomenclature system and highlights examples of existing ambiguities and remedies for them. This nomenclature is intended to serve as a\ standard of reference for the study of the brain of Drosophila and other insects.

}, issn = {1097-4199}, doi = {10.1016/j.neuron.2013.12.017}, author = {Ito, Kei and Shinomiya, Kazunori and Ito, Masayoshi and Armstrong, J Douglas and Boyan, George and Hartenstein, Volker and Harzsch, Steffen and Heisenberg, Martin and Homberg, Uwe and Jenett, Arnim and Keshishian, Haig and Restifo, Linda L and R{\"o}ssler, Wolfgang and Simpson, Julie H and Strausfeld, Nicholas J and Strauss, Roland and Vosshall, Leslie B} } @article {5423, title = {A GAL4-driver line resource for Drosophila neurobiology.}, journal = {Cell Reports}, volume = {2}, year = {2012}, month = {2012 Oct 25}, pages = {991-1001}, abstract = {

We established a collection of 7,000 transgenic lines of Drosophila melanogaster. Expression of GAL4 in each line is controlled by a different, defined fragment of genomic DNA that serves as a transcriptional enhancer. We used confocal microscopy of dissected nervous systems to determine the expression patterns driven by each fragment in the adult brain and ventral nerve cord. We present image data on 6,650 lines. Using both manual and machine-assisted annotation, we describe the expression patterns in the most useful lines. We illustrate the utility of these data for identifying novel neuronal cell types, revealing brain asymmetry, and describing the nature and extent of neuronal shape stereotypy. The GAL4 lines allow expression of exogenous genes in distinct, small subsets of the adult nervous system. The set of DNA fragments, each driving a documented expression pattern, will facilitate the generation of additional constructs for manipulating neuronal function. synapse was substantially elevated, at the endocytic zone there was no enhanced polymerization activity. We conclude that actin subserves spatially diverse, independently regulated processes throughout spines. Perisynaptic actin forms a uniquely dynamic structure well suited for direct, active regulation of the synapse.

For the overall strategy and methods used to produce the GAL4 lines:
Pfeiffer, B.D., Jenett, A., Hammonds, A.S., Ngo, T.T., Misra, S., Murphy, C., Scully, A., Carlson, J.W., Wan, K.H., Laverty, T.R., Mungall, C., Svirskas, R., Kadonaga, J.T., Doe, C.Q., Eisen, M.B., Celniker, S.E., Rubin, G.M. (2008). Tools for neuroanatomy and neurogenetics in Drosophila. Proc. Natl. Acad. Sci. USA 105, 9715-9720. http://www.pnas.org/content/105/28/9715.full.pdf+html synapse was substantially elevated, at the endocytic zone there was no enhanced polymerization activity. We conclude that actin subserves spatially diverse, independently regulated processes throughout spines. Perisynaptic actin forms a uniquely dynamic structure well suited for direct, active regulation of the synapse.

For data on expression in the embryo:
Manning, L., Purice, M.D., Roberts, J., Pollard, J.L., Bennett, A.L., Kroll, J.R., Dyukareva, A.V., Doan, P.N., Lupton, J.R., Strader, M.E., Tanner, S., Bauer, D., Wilbur, A., Tran, K.D., Laverty, T.R., Pearson, J.C., Crews, S.T., Rubin, G.M., and Doe, C.Q. (2012) Annotated embryonic CNS expression patterns of 5000 GMR GAL4 lines: a resource for manipulating gene expression and analyzing cis-regulatory motifs. Cell Reports (2012) Doi: 10.1016/j.celrep.2012.09.009 http://www.cell.com/cell-reports/fulltext/S2211-1247(12)00290-2 synapse was substantially elevated, at the endocytic zone there was no enhanced polymerization activity. We conclude that actin subserves spatially diverse, independently regulated processes throughout spines. Perisynaptic actin forms a uniquely dynamic structure well suited for direct, active regulation of the synapse.

For data on expression in imaginal discs:
Jory, A., Estella, C., Giorgianni, M.W., Slattery, M., Laverty, T.R., Rubin, G.M., and Mann, R.S. (2012) A survey of 6300 genomic fragments for cis-regulatory activity in the imaginal discs of Drosophila melanogaster. Cell Reports (2012) Doi: 10.1016/j.celrep.2012.09.010 http://www.cell.com/cell-reports/fulltext/S2211-1247(12)00291-4 synapse was substantially elevated, at the endocytic zone there was no enhanced polymerization activity. We conclude that actin subserves spatially diverse, independently regulated processes throughout spines. Perisynaptic actin forms a uniquely dynamic structure well suited for direct, active regulation of the synapse.

For data on expression in the larval nervous system:
Li, H.-H., Kroll, J.R., Lennox, S., Ogundeyi, O., Jeter, J., Depasquale, G., and Truman, J.W. (2013) A GAL4 driver resource for developmental and behavioral studies on the larval CNS of Drosophila. Cell Reports (submitted).

}, issn = {2211-1247}, doi = {10.1016/j.celrep.2012.09.011}, author = {Jenett, Arnim and Rubin, Gerald M and Ngo, Teri-T B and Shepherd, David and Murphy, Christine and Dionne, Heather and Pfeiffer, Barret D and Cavallaro, Amanda and Hall, Donald and Jeter, Jennifer and Iyer, Nirmala and Fetter, Dona and Hausenfluck, Joanna H and Peng, Hanchuan and Trautman, Eric T and Svirskas, Robert R and Myers, Eugene W and Iwinski, Zbigniew R and Aso, Yoshinori and Depasquale, Gina M and Enos, Adrianne and Hulamm, Phuson and Lam, Shing Chun Benny and Li, Hsing-Hsi and Laverty, Todd R and Long, Fuhui and Qu, Lei and Murphy, Sean D and Rokicki, Konrad and Safford, Todd and Shaw, Kshiti and Simpson, Julie H and Sowell, Allison and Tae, Susana and Yu, Yang and Zugates, Christopher T} } @article {4157, title = {BrainAligner: 3D registration atlases of Drosophila brains.}, journal = {Nature Methods}, volume = {8}, year = {2011}, month = {2011 Jun}, pages = {493-500}, abstract = {

Analyzing Drosophila melanogaster neural expression patterns in thousands of three-dimensional image stacks of individual brains requires registering them into a canonical framework based on a fiducial reference of neuropil morphology. Given a target brain labeled with predefined landmarks, the BrainAligner program automatically finds the corresponding landmarks in a subject brain and maps it to the coordinate system of the target brain via a deformable warp. Using a neuropil marker (the antibody nc82) as a reference of the brain morphology and a target brain that is itself a statistical average of data for 295 brains, we achieved a registration accuracy of 2 μm on average, permitting assessment of stereotypy, potential connectivity and functional mapping of the adult fruit fly brain. We used BrainAligner to generate an image pattern atlas of 2954 registered brains containing 470 different expression patterns that cover all the major compartments of the fly brain.

}, keywords = {Algorithms, Animals, Brain, Computer-Assisted, Drosophila melanogaster, Drosophila Proteins, Gene Expression, Genetically Modified, Green Fluorescent Proteins, Image Processing, Neuropil, Recombinant Proteins, Software, Transcription Factors}, issn = {1548-7105}, doi = {10.1038/nmeth.1602}, author = {Peng, Hanchuan and Chung, Phuong and Long, Fuhui and Qu, Lei and Jenett, Arnim and Seeds, Andrew M and Myers, Eugene W and Simpson, Julie H} } @article {1513, title = {Drosophila brainbow: a recombinase-based fluorescence labeling technique to subdivide neural expression patterns.}, journal = {Nature Methods}, volume = {8}, year = {2011}, month = {2011 Mar}, pages = {253-9}, abstract = {

We developed a multicolor neuron labeling technique in Drosophila melanogaster that combines the power to specifically target different neural populations with the label diversity provided by stochastic color choice. This adaptation of vertebrate Brainbow uses recombination to select one of three epitope-tagged proteins detectable by immunofluorescence. Two copies of this construct yield six bright, separable colors. We used Drosophila Brainbow to study the innervation patterns of multiple antennal lobe projection neuron lineages in the same preparation and to observe the relative trajectories of individual aminergic neurons. Nerve bundles, and even individual neurites hundreds of micrometers long, can be followed with definitive color labeling. We traced motor neurons in the subesophageal ganglion and correlated them to neuromuscular junctions to identify their specific proboscis muscle targets. The ability to independently visualize multiple lineage or neuron projections in the same preparation greatly advances the goal of mapping how neurons connect into circuits.

}, issn = {1548-7105}, doi = {10.1038/nmeth.1566}, author = {Hampel, Stefanie and Chung, Phuong and McKellar, Claire E and Hall, Donald and Looger, Loren L and Simpson, Julie H} } @article {4156, title = {Genetic manipulation of genes and cells in the nervous system of the fruit fly.}, journal = {Neuron}, volume = {72}, year = {2011}, month = {2011 Oct 20}, pages = {202-30}, abstract = {

Research in the fruit fly Drosophila melanogaster has led to insights in neural development, axon guidance, ion channel function, synaptic transmission, learning and memory, diurnal rhythmicity, and neural disease that have had broad implications for neuroscience. Drosophila is currently the eukaryotic model organism that permits the most sophisticated in\ vivo manipulations to address the function of neurons and neuronally expressed genes. Here, we summarize many of the techniques that help assess the role of specific neurons by labeling, removing, or altering their activity. We also survey genetic manipulations to identify and characterize neural genes by mutation, overexpression, and protein labeling. Here, we attempt to acquaint the reader with available options and contexts to apply these methods.

}, issn = {1097-4199}, doi = {10.1016/j.neuron.2011.09.021}, author = {Venken, Koen J T and Simpson, Julie H and Bellen, Hugo J} } @article {4158, title = {Mutation of the Drosophila vesicular GABA transporter disrupts visual figure detection.}, journal = {The Journal of Experimental Biology}, volume = {213}, year = {2010}, month = {2010 May}, pages = {1717-30}, abstract = {

The role of gamma amino butyric acid (GABA) release and inhibitory neurotransmission in regulating most behaviors remains unclear. The vesicular GABA transporter (VGAT) is required for the storage of GABA in synaptic vesicles and provides a potentially useful probe for inhibitory circuits. However, specific pharmacologic agents for VGAT are not available, and VGAT knockout mice are embryonically lethal, thus precluding behavioral studies. We have identified the Drosophila ortholog of the vesicular GABA transporter gene (which we refer to as dVGAT), immunocytologically mapped dVGAT protein expression in the larva and adult and characterized a dVGAT(minos) mutant allele. dVGAT is embryonically lethal and we do not detect residual dVGAT expression, suggesting that it is either a strong hypomorph or a null. To investigate the function of VGAT and GABA signaling in adult visual flight behavior, we have selectively rescued the dVGAT mutant during development. We show that reduced GABA release does not compromise the active optomotor control of wide-field pattern motion. Conversely, reduced dVGAT expression disrupts normal object tracking and figure-ground discrimination. These results demonstrate that visual behaviors are segregated by the level of GABA signaling in flies, and more generally establish dVGAT as a model to study the contribution of GABA release to other complex behaviors.

}, keywords = {Alleles, Amino Acid Sequence, Animal, Animals, Behavior, Brain, Drosophila melanogaster, Drosophila Proteins, Fixation, Ganglia, Gene Knockdown Techniques, Larva, Mice, Molecular Sequence Data, Movement, Mutation, Ocular, Protein Transport, Synaptic Vesicles, Transgenes, Vesicular Inhibitory Amino Acid Transport Proteins, Visual Perception}, issn = {1477-9145}, doi = {10.1242/jeb.036053}, author = {Fei, Hao and Chow, Dawnis M and Chen, Audrey and Romero-Calder{\'o}n, Rafael and Ong, Wei S and Ackerson, Larry C and Maidment, Nigel T and Simpson, Julie H and Frye, Mark A and Krantz, David E} } @article {2328, title = {VAA3D enables real-time 3D visualization and quantitative analysis of large-scale biological image data sets.}, journal = {Nature Biotechnology}, volume = {28}, year = {2010}, month = {2010 Apr}, pages = {348-53}, abstract = {

The V3D system provides three-dimensional (3D) visualization of gigabyte-sized microscopy image stacks in real time on current laptops and desktops. V3D streamlines the online analysis, measurement and proofreading of complicated image patterns by combining ergonomic functions for selecting a location in an image directly in 3D space and for displaying biological measurements, such as from fluorescent probes, using the overlaid surface objects. V3D runs on all major computer platforms and can be enhanced by software plug-ins to address specific biological problems. To demonstrate this extensibility, we built a V3D-based application, V3D-Neuron, to reconstruct complex 3D neuronal structures from high-resolution brain images. V3D-Neuron can precisely digitize the morphology of a single neuron in a fruitfly brain in minutes, with about a 17-fold improvement in reliability and tenfold savings in time compared with other neuron reconstruction tools. Using V3D-Neuron, we demonstrate the feasibility of building a 3D digital atlas of neurite tracts in the fruitfly brain.

}, keywords = {Computer Graphics, Computer-Assisted, Databases, Factual, Image Interpretation, Imaging, Information Storage and Retrieval, Microscopy, Radiology Information Systems, Three-Dimensional, User-Computer Interface}, issn = {1546-1696}, doi = {10.1038/nbt.1612}, author = {Peng, Hanchuan and Ruan, Zongcai and Long, Fuhui and Simpson, Julie H and Myers, Eugene W} } @article {1521, title = {Mapping and manipulating neural circuits in the fly brain.}, journal = {Advances in Genetics}, volume = {65}, year = {2009}, month = {2009}, pages = {79-143}, abstract = {

Drosophila is a marvelous system to study the underlying principles that govern how neural circuits govern behaviors. The scale of the fly brain (approximately 100,000 neurons) and the complexity of the behaviors the fly can perform make it a tractable experimental model organism. In addition, 100 years and hundreds of labs have contributed to an extensive array of tools and techniques that can be used to dissect the function and organization of the fly nervous system. This review discusses both the conceptual challenges and the specific tools for a neurogenetic approach to circuit mapping in Drosophila.

}, keywords = {Animal, Animals, Behavior, Brain, Chromosome Mapping, Drosophila, Nerve Net, Neurons}, issn = {0065-2660}, doi = {10.1016/S0065-2660(09)65003-3}, author = {Simpson, Julie H} } @article {1517, title = {Ectopic expression in the giant fiber system of Drosophila reveals distinct roles for roundabout (Robo), Robo2, and Robo3 in dendritic guidance and synaptic connectivity.}, journal = {The Journal of Neuroscience: The Official Journal of the Society for Neuroscience}, volume = {22}, year = {2002}, month = {2002 Apr 15}, pages = {3117-29}, abstract = {

The Roundabout (Robo) receptors have been intensively studied for their role in regulating axon guidance in the embryonic nervous system, whereas a role in dendritic guidance has not been explored. In the adult giant fiber system of Drosophila, we have revealed that ectopic Robo expression can regulate the growth and guidance of specific motor neuron dendrites, whereas Robo2 and Robo3 have no effect. We also show that the effect of Robo on dendritic guidance can be suppressed by Commissureless coexpression. Although we confirmed a role for all three Robo receptors in giant fiber axon guidance, the strong axon guidance alterations caused by overexpression of Robo2 or Robo3 have no effect on synaptic connectivity. In contrast, Robo overexpression in the giant fiber seems to directly interfere with synaptic function. We conclude that axon guidance, dendritic guidance, and synaptogenesis are separable processes and that the different Robo family members affect them distinctly.

}, keywords = {Amino Acid Motifs, Animals, Axons, Dendrites, Drosophila, Drosophila Proteins, Electric Stimulation, Excitatory Postsynaptic Potentials, Gene Expression, Genetically Modified, Immunologic, Insect Proteins, Membrane Proteins, Motor Neurons, Nerve Fibers, Nerve Tissue Proteins, Phenotype, Pupa, Reaction Time, Receptors, Synapses}, issn = {1529-2401}, doi = {20026291}, author = {Godenschwege, Tanja A and Simpson, Julie H and Shan, Xiaoliang and Bashaw, Greg J and Goodman, Corey S and Murphey, Rodney K} }