AUTHOR=Lv Mingyue , Xu Xiao , Zhang Xinyang , Yuwen Bo , Zhang Long 

TITLE=Serotonin/GABA receptors modulate odor input to olfactory receptor neuron in locusts

JOURNAL=Frontiers in Cellular Neuroscience

VOLUME=17

YEAR=2023

URL=https://www.frontiersin.org/journals/cellular-neuroscience/articles/10.3389/fncel.2023.1156144

DOI=10.3389/fncel.2023.1156144

ISSN=1662-5102

ABSTRACT=<sec><title>Introduction</title><p>Serotonin (5-hydroxytryptamine; 5-HT) and GABA (γ-aminobutyric acid) are involved in the regulation of behaviors in the central nervous system. However, it remains unclear whether they modulate olfaction in the peripheral nervous system, and how they modulate olfaction.</p></sec><sec><title>Methods and results</title><p>One 5-HT receptor sequence (<italic>Lmig</italic>5-HT2) and one GABA receptor sequence (<italic>Lmig</italic>GABAb) were identified in locust antennae by transcriptome analysis and polymerase chain reaction experiments. <italic>In situ</italic> hybridization localized <italic>Lmig</italic>5-HT2 to accessory cells, while <italic>Lmig</italic>GABAb was localized to olfactory receptor neurons (ORNs) in locust chemosensilla. Single-unit electrophysiological recordings combined with RNA interference (RNAi) experiments indicated ORNs of locusts with knockdown of <italic>Lmig</italic>5-HT2 (ds-<italic>Lmig</italic>5-HT2) and <italic>Lmig</italic>GABAb (ds-<italic>Lmig</italic>GABAb) to some odors had significantly higher responses than wild-type and control locusts in the dose-dependent responses. Moreover, the gaps between the responses of ORNs of RNAi ones and those of wild-type and ds-GFP enlarged with an increase in concentrations of odors.</p></sec><sec><title>Discussion</title><p>Taken together, our findings suggest that 5-HT, GABA, and their receptors exist in the insect peripheral nervous system and that they may function as negative feedback to ORNs and contribute to a fine-tuning mechanism for olfaction in the peripheral nervous system.</p></sec>