Neuropeptide feedback modifies odor-evoked dynamics in Caenorhabditis elegans olfactory neurons

Top Cited Papers
Open Access
Publisher Website
Google Scholar
Abstract
Odors, via the olfactory AWC neurons, trigger food searching in C. elegans. This study shows that the peptide NLP-1, co-released with glutamate from AWC neurons, acts to limit searching locomotion through a feedback loop that involves activation of the receptor NPR-11 on AIA interneurons and release of another peptide, INS-1, from the AIA neurons. Many neurons release classical transmitters together with neuropeptide co-transmitters whose functions are incompletely understood. Here we define the relationship between two transmitters in the olfactory system of C. elegans, showing that a neuropeptide-to-neuropeptide feedback loop alters sensory dynamics in primary olfactory neurons. The AWC olfactory neuron is glutamatergic and also expresses the peptide NLP-1. Worms with nlp-1 mutations show increased AWC-dependent behaviors, suggesting that NLP-1 limits the normal response. The receptor for NLP-1 is the G protein-coupled receptor NPR-11, which acts in postsynaptic AIA interneurons. Feedback from AIA interneurons modulates odor-evoked calcium dynamics in AWC olfactory neurons and requires INS-1, a neuropeptide released from AIA. The neuropeptide feedback loop dampens behavioral responses to odors on short and long timescales. Our results point to neuronal dynamics as a site of behavioral regulation and reveal the ability of neuropeptide feedback to remodel sensory networks on multiple timescales.