Alleviation of thermal nociception depends on heat-sensitive neurons and a TRP channel in the brain

TitleAlleviation of thermal nociception depends on heat-sensitive neurons and a TRP channel in the brain
Publication TypeJournal Article
Year of Publication2023
AuthorsLiu J, Liu W, Thakur D, Mack J, Spina A, Montell C
JournalCurr Biol
Volume33
Issue12
Pagination2397-2406.e6
Date Published2023 Jun 19
ISSN1879-0445
KeywordsAnimals, Brain, Drosophila melanogaster, Drosophila Proteins, Hot Temperature, Humans, Mammals, Neurons, Nociception, Pain
Abstract

Acute avoidance of dangerous temperatures is critical for animals to prevent or minimize injury. Therefore, surface receptors have evolved to endow neurons with the capacity to detect noxious heat so that animals can initiate escape behaviors. Animals including humans have evolved intrinsic pain-suppressing systems to attenuate nociception under some circumstances. Here, using Drosophila melanogaster, we uncovered a new mechanism through which thermal nociception is suppressed. We identified a single descending neuron in each brain hemisphere, which is the center for suppression of thermal nociception. These Epi neurons, for Epione-the goddess of soothing of pain-express a nociception-suppressing neuropeptide Allatostatin C (AstC), which is related to a mammalian anti-nociceptive peptide, somatostatin. Epi neurons are direct sensors for noxious heat, and when activated they release AstC, which diminishes nociception. We found that Epi neurons also express the heat-activated TRP channel, Painless (Pain), and thermal activation of Epi neurons and the subsequent suppression of thermal nociception depend on Pain. Thus, while TRP channels are well known to sense noxious temperatures to promote avoidance behavior, this work reveals the first role for a TRP channel for detecting noxious temperatures for the purpose of suppressing rather than enhancing nociception behavior in response to hot thermal stimuli.

DOI10.1016/j.cub.2023.04.055
Alternate JournalCurr Biol
PubMed ID37201520
PubMed Central IDPMC10330845
Grant ListR01 DC007864 / DC / NIDCD NIH HHS / United States
R01 EY008117 / EY / NEI NIH HHS / United States