Nociceptor clock genes control excitability and pain perception in a sex and time-dependent manner

Both sex and circadian rhythms, governed by clock genes, seem to play a significant role in modulating pain perception. However, the potential interaction between circadian rhythms and sex differences in nociception at the peripheral level has been largely overlooked.

Here, we first report that DRGs from mice express clock genes in a time- and sex-dependent manner. Using whole-cell recordings in whole-mounted DRGs and optogenetic stimulation of Nav1.8-expressing neurons, we demonstrate that male nociceptors exhibit reduced excitability during the night, while female nociceptor excitability remains stable across time points. Disruption of the core clock gene Bmal1 in Nav1.8-expressing neurons not only diminished nociceptor activity but also abolished the nighttime reduction in heat sensitivity, highlighting a pivotal role for the molecular clock in regulating nociception.