Bobkov, Y. V. | Search bioRxiv

bioRxiv2022

Anion efflux mediates transduction in hair cells of zebrafish lateral line

Hair cells are the principal sensory receptors of the vertebrate auditory system, and transduce sounds with mechanically-gated ion channels that permit cations to flow from the surrounding endolymph into the cells. The lateral line of zebrafish has served as a key model system for understanding hair cell physiology and development, and it has often been speculated that these hair cells employ a similar transduction mechanism. In this study, we demonstrate that the hair cells are exposed to an unregulated external environment with cation concentrations that are too low to support transduction. Instead, our results indicate that hair cell excitation is mediated by a fundamentally different mechanism involving the outward flow of anions.

neuroscience↗

bioRxiv2019

Inhibitory signaling in mammalian olfactory transduction potentially mediated by Gαo

Olfactory GPCRs (ORs) in mammalian olfactory receptor neurons (ORNs) mediate excitation through the Gs family member Golf. Here we tentatively associate a second G protein, Go, with inhibitory signalling in mammalian olfactory transduction by first showing that odor evoked phosphoinositide 3-kinase (PI3K)-dependent inhibition of signal transduction is absent in the native ORNs of mice carrying a conditional OMP-Cre based knockout of Go. We then identify an OR from native rat ORNs that are activated by octanol through cyclic nucleotide signaling and inhibited by citral in a PI3K-dependent manner. We show that the OR activates cyclic nucleotide signaling and PI3K signaling in a manner that reflects its functionality in native ORNs. Our findings lay the groundwork to explore the interesting possibility that ORs can interact with two different G proteins in a functionally identified, ligand-dependent manner to mediate opponent signaling in mature mammalian ORNs.

neuroscience↗