Biology subjects

Rubin, G. M.

Publications and source records attributed to Rubin, G. M..

5 recordsLinked to original sources

bioRxiv2018

Neural circuit basis of aversive odour processing in Drosophila from sensory input to descending output.

Evolution has shaped nervous systems to produce stereotyped behavioural responses to ethologically relevant stimuli. For example when laying eggs, female Drosophila avoid geosmin, an odorant produced by toxic moulds. Here we identify second, third, and fourth order neurons required for this innate olfactory aversion. Connectomics data place these neurons in a complete synaptic circuit from sensory input to descending output. We find multiple levels of valence-specific convergence, including a novel form of axo-axonic input onto second order neurons conveying another danger signal, the pheromone of parasitoid wasps. However, we also observe extensive divergence: second order geosmin neurons connect with a diverse array of 80 third order cell types. We find a pattern of convergence of aversive odour channels at this level. Crossing one more synaptic layer, we identified descending neurons critical for egg-laying aversion. Our data suggest a transition from a labelled line organisation in the periphery to a highly distributed central brain representation that is then coupled to distinct descending pathways.

neuroscience↗

bioRxiv2018

A genetic, genomic, and computational resource for exploring neural circuit function

The anatomy of many neural circuits is being characterized with increasing resolution, but their molecular properties remain mostly unknown. Here, we characterize gene expression patterns in distinct neural cell types of the Drosophila visual system using genetic lines to access individual cell types, the TAPIN-seq method to measure their transcriptomes, and a probabilistic method to interpret these measurements. We used these tools to build a resource of high-resolution transcriptomes for 100 driver lines covering 67 cell types, available at http://www.opticlobe.com. Combining these transcriptomes with recently reported connectomes helps characterize how information is transmitted and processed across a range of scales, from individual synapses to circuit pathways. We describe examples that include identifying neurotransmitters, including cases of co-release, generating functional hypotheses based on receptor expression, as well as identifying strong commonalities between different cell types.\n\nHighlightsO_LITranscriptomes reveal transmitters and receptors expressed in Drosophila visual neurons\nC_LIO_LITandem affinity purification of intact nuclei (TAPIN) enables neuronal genomics\nC_LIO_LITAPIN-seq and genetic drivers establish transcriptomes of 67 Drosophila cell types\nC_LIO_LIProbabilistic modeling simplifies interpretation of large transcriptome catalogs\nC_LI

neuroscience↗

bioRxiv2018

Cortical Column and Whole Brain Imaging of Neural Circuits with Molecular Contrast and Nanoscale Resolution

Optical and electron microscopy have made tremendous inroads in understanding the complexity of the brain, but the former offers insufficient resolution to reveal subcellular details and the latter lacks the throughput and molecular contrast to visualize specific molecular constituents over mm-scale or larger dimensions. We combined expansion microscopy and lattice light sheet microscopy to image the nanoscale spatial relationships between proteins across the thickness of the mouse cortex or the entire Drosophila brain, including synaptic proteins at dendritic spines, myelination along axons, and presynaptic densities at dopaminergic neurons in every fly neuropil domain. The technology should enable statistically rich, large scale studies of neural development, sexual dimorphism, degree of stereotypy, and structural correlations to behavior or neural activity, all with molecular contrast.\n\nOne Sentence SummaryCombined expansion and lattice light sheet microscopy enables high speed, nanoscale molecular imaging of neural circuits over large volumes.

neuroscience↗

bioRxiv2017

Genetic reagents for making split-GAL4 lines in Drosophila

The ability to reproducibly target expression of transgenes to small, defined subsets of cells is a key experimental tool for understanding many biological processes. The Drosophila nervous system contains thousands of distinct cell types and it has generally not been possible to limit expression to one or a few cell types when using a single segment of genomic DNA as an enhancer to drive expression. Intersectional methods, in which expression of the transgene only occurs where two different enhancers overlap in their expression patterns, can be used to achieve the desired specificity. This report describes a set of over 2,800 transgenic lines for use with the split-GAL4 intersectional method.

neuroscience↗

bioRxiv2017

Memory retrieval recruits both innate and learned olfactoryprocessing centres in Drosophila

Animals can show either learned or innate behavioral responses to a given stimulus. How these circuits interact to produce an appropriate behavioral response is unknown. In the Drosophila olfactory system, the lateral horn (LH) and the mushroom body (MB) are thought to mediate innate and learned olfactory behavior respectively, although the function of the LH has not been directly tested. Here we identify two LH cell-types (PD2a1/b1) that receive input from an MB output neuron required for recall of aversive olfactory memories. In contrast to the model above we find that PD2a1/b1 are required for aversive memory retrieval. PD2a1/b1 activity is modulated by training, indicating that memory information is passed to the innate olfactory processing centre. We map the connectivity of PD2a1/b1 to other olfactory neurons with connectomic data. This provides a circuit mechanism by which learned and unlearned olfactory information can interact to produce appropriate behavior.

neuroscience↗