Endogenous opioid signaling in the retina modulates sleep/wake activity in mice.

ABSTRACT: Circadian sleep/wake rhythms are synchronized to environmental light/dark cycles in a process known as photoentrainment. We have previously shown that activation of β-endorphin-preferring μ-opioid receptors (MORs) inhibits the light-evoked firing of intrinsically photosensitive retinal ganglion cells (ipRGCs), the sole conduits of photoentrainment. Although we have shown that β-endorphin is expressed in the adult mouse retina, the conditions under which β-endorphin is expressed are unknown. Moreover, it is unclear whether endogenous activation of the MORs expressed by ipRGCs modulates the photoentrainment of sleep/wake cycles. To elucidate this, we first measured the mRNA expression of β-endorphin's precursor, proopiomelanocortin (POMC), at various times of day by quantitative reverse-tran

SUBMITTER: Berezin CT 

PROVIDER: S-EPMC9254600 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature