@article {65040, title = {Local synaptic inputs support opposing, network-specific odor representations in a widely projecting modulatory neuron.}, journal = {eLife}, volume = {8}, year = {2019}, month = {2 Jul 2019}, abstract = {

Serotonin plays different roles across networks within the same sensory modality. Previously, we used whole-cell electrophysiology in\ Drosophila\ to show that serotonergic neurons innervating the first olfactory relay are inhibited by odorants (Zhang and Gaudry, 2016). Here we show that network-spanning serotonergic neurons segregate information about stimulus features, odor intensity and identity, by using opposing coding schemes in different olfactory neuropil. A pair of serotonergic neurons (the CSDns) innervate the antennal lobe and lateral horn, which are first and second order neuropils. CSDn processes in the antennal lobe are inhibited by odors in an identity independent manner. In the lateral horn, CSDn processes are excited in an odor identity dependent manner. Using functional imaging, modeling, and EM reconstruction, we demonstrate that antennal lobe derived inhibition arises from local GABAergic inputs and acts as a means of gain control on branch specific inputs that the CSDns receive within the lateral horn.

}, doi = {10.7554/eLife.46839}, url = {https://elifesciences.org/articles/46839https://cdn.elifesciences.org/articles/46839/elife-46839-v1.pdfhttps://cdn.elifesciences.org/articles/46839/elife-46839-v1.xml}, author = {Zhang, Xiaonan and Coates, Kaylynn and Dacks, Andrew M and Gunay, Cengiz and Lauritzen, J Scott and Li, Feng and Calle-Schuler, Steven A and Bock, Davi and Gaudry, Quentin} } @article {59913, title = {Regulation of modulatory cell activity across olfactory structures in Drosophila melanogaster.}, journal = {bioRxiv}, year = {2019}, month = {2019 Jan 16}, abstract = {

All centralized nervous systems possess modulatory neurons that arborize broadly across multiple brain regions. Such modulatory systems are critical for proper sensory, motor, and cognitive processing. How single modulatory neurons integrate into circuits within their target destination remains largely unexplored due to difficulties in both labeling individual cells and imaging across distal parts of the CNS. Here, we take advantage of an identified modulatory neuron in Drosophila that arborizes in multiple olfactory neuropils. We demonstrate that this serotonergic neuron has opposing odor responses in its neurites of the antennal lobe and lateral horn, first and second order olfactory neuropils respectively. Specifically, processes of this neuron in the antennal lobe have responses that are inhibitory and odor-independent, while lateral horn responses are excitatory and odor-specific. The results show that widespread modulatory neurons may not function purely as integrate-and-fire cells, but rather their transmitter release is locally regulated based on neuropil. As nearly all vertebrate and invertebrate neurons are subject to synaptic inputs along their dendro-axonic axis, it is likely that our findings generalize across phylogeny and other broadly-projecting modulatory systems.

}, doi = {10.1101/522177}, author = {Zhang, Xiaonan and Coates, Kaylynn and Dacks, Andrew and Gunay, Cengiz and Lauritzen, J Scott and Li, Feng and Calle-Schuler, Steven A and Bock, Davi D and Gaudry, Quentin} }