@article {48494, title = {Representations of Novelty and Familiarity in a Mushroom Body Compartment.}, journal = {Cell}, volume = {169}, year = {2017}, month = {2017 May 09}, pages = {956-69}, abstract = {

Animals exhibit a behavioral response to novel sensory stimuli about which they have no prior knowledge. We have examined the neural and behavioral correlates of novelty and familiarity in the olfactory system of Drosophila. Novel odors elicit strong activity in output neurons (MBONs) of the α{\textquoteright}3 compartment of the mushroom body that is rapidly suppressed upon repeated exposure to the same odor. This transition in neural activity upon familiarization requires odor-evoked activity in the dopaminergic neuron innervating this compartment. Moreover, exposure of a fly to novel odors evokes an alerting response that can also be elicited by optogenetic activation of α{\textquoteright}3 MBONs. Silencing these MBONs eliminates the alerting behavior. These data suggest that the α{\textquoteright}3 compartment plays a causal role in the behavioral response to novel and familiar stimuli as a consequence of dopamine-mediated plasticity at the Kenyon cell-MBONα{\textquoteright}3 synapse.

}, issn = {1097-4172}, doi = {10.1016/j.cell.2017.04.028}, author = {Hattori, Daisuke and Aso, Yoshinori and Swartz, Kurtis J and Rubin, Gerald M and Abbott, L F and Axel, Richard} } @article {45810, title = {The neuronal architecture of the mushroom body provides a logic for associative learning.}, journal = {eLife}, volume = {3}, year = {2014}, month = {2014 Dec 23}, abstract = {

We identified the neurons comprising the Drosophila mushroom body (MB), an associative center in invertebrate brains, and provide a comprehensive map describing their potential connections. Each of the 21 MB output neuron (MBON) types elaborates segregated dendritic arbors along the parallel axons of \~{}2000 Kenyon cells, forming 15 compartments that collectively tile the MB lobes. MBON axons project to five discrete neuropils outside of the MB and three MBON types form a feedforward network in the lobes. Each of the 20 dopaminergic neuron (DAN) types projects axons to one, or at most two, of the MBON compartments. Convergence of DAN axons on compartmentalized Kenyon cell-MBON synapses creates a highly ordered unit that can support learning to impose valence on sensory representations. The elucidation of the complement of neurons of the MB provides a comprehensive anatomical substrate from which one can infer a functional logic of associative olfactory learning and memory.

}, issn = {2050-084X}, doi = {10.7554/eLife.04577}, author = {Aso, Yoshinori and Hattori, Daisuke and Yu, Yang and Johnston, Rebecca M and Iyer, Nirmala A and Ngo, Teri-Tb and Dionne, Heather and Abbott, Lf and Axel, Richard and Tanimoto, Hiromu and Rubin, Gerald M} } @article {4295, title = {A dimorphic pheromone circuit in Drosophila from sensory input to descending output.}, journal = {Nature}, volume = {468}, year = {2010}, month = {2010 Dec 2}, pages = {686-90}, abstract = {

Drosophila show innate olfactory-driven behaviours that are observed in naive animals without previous learning or experience, suggesting that the neural circuits that mediate these behaviours are genetically programmed. Despite the numerical simplicity of the fly nervous system, features of the anatomical organization of the fly brain often confound the delineation of these circuits. Here we identify a neural circuit responsive to cVA, a pheromone that elicits sexually dimorphic behaviours. We have combined neural tracing using an improved photoactivatable green fluorescent protein (PA-GFP) with electrophysiology, optical imaging and laser-mediated microlesioning to map this circuit from the activation of sensory neurons in the antennae to the excitation of descending neurons in the ventral nerve cord. This circuit is concise and minimally comprises four neurons, connected by three synapses. Three of these neurons are overtly dimorphic and identify a male-specific neuropil that integrates inputs from multiple sensory systems and sends outputs to the ventral nerve cord. This neural pathway suggests a means by which a single pheromone can elicit different behaviours in the two sexes.

}, keywords = {Acetates, Animal, Animals, Arthropod Antennae, Drosophila melanogaster, Drosophila Proteins, Female, Male, Nerve Tissue Proteins, Neuroanatomical Tract-Tracing Techniques, Odors, Oleic Acids, Olfactory Pathways, Olfactory Perception, Pheromones, Physical Stimulation, Sensory Receptor Cells, Sex Characteristics, Sexual Behavior, Transcription Factors}, issn = {1476-4687}, doi = {10.1038/nature09554}, author = {Ruta, Vanessa and Datta, Sandeep Robert and Vasconcelos, Maria Lu{\'\i}sa and Freeland, Jessica and Looger, Loren L and Axel, Richard} }