Asymmetric ephaptic inhibition between compartmentalized olfactory receptor neurons.

TitleAsymmetric ephaptic inhibition between compartmentalized olfactory receptor neurons.
Publication TypeJournal Article
Year of Publication2019
AuthorsZhang Y, Tsang TKi, Bushong EA, Chu L-A, Chiang A-S, Ellisman MH, Reingruber J, Su C-Y
JournalNat Commun
Date Published2019 04 05
KeywordsAnimals, Drosophila, Imaging, Three-Dimensional, Models, Biological, Olfactory Pathways, Olfactory Receptor Neurons, Sensilla, Smell

In the Drosophila antenna, different subtypes of olfactory receptor neurons (ORNs) housed in the same sensory hair (sensillum) can inhibit each other non-synaptically. However, the mechanisms underlying this underexplored form of lateral inhibition remain unclear. Here we use recordings from pairs of sensilla impaled by the same tungsten electrode to demonstrate that direct electrical ("ephaptic") interactions mediate lateral inhibition between ORNs. Intriguingly, within individual sensilla, we find that ephaptic lateral inhibition is asymmetric such that one ORN exerts greater influence onto its neighbor. Serial block-face scanning electron microscopy of genetically identified ORNs and circuit modeling indicate that asymmetric lateral inhibition reflects a surprisingly simple mechanism: the physically larger ORN in a pair corresponds to the dominant neuron in ephaptic interactions. Thus, morphometric differences between compartmentalized ORNs account for highly specialized inhibitory interactions that govern information processing at the earliest stages of olfactory coding.

Alternate JournalNat Commun
PubMed ID30952860
PubMed Central IDPMC6451019
Grant ListP41 GM103412 / GM / NIGMS NIH HHS / United States
R01 DC015519 / DC / NIDCD NIH HHS / United States
IRG Funded