Anticholinergic agents do not block light-induced circadian phase shifts.
Depletion of brain acetylcholine (ACh) stores by central infusions of hemicholinium-3 (HC-3) did not prevent the circadian phase-shifting effects of subsequent light pulses in rats. Animals treated with atropine likewise had normal responses to light pulses. Neither delay nor advance shifts were prevented. These data do not support the view that ACh is the primary mediator of photoentrainment in the rat. The previously reported effects of carbachol injections may be non-specific.
D000109:Acetylcholine / Q000502:physiology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001921:Brain / Q000502:physiology*; D002940:Circadian Rhythm / Q000187:drug effects; D006426:Hemicholinium 3 / Q000494:pharmacology; D008027:Light; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D006426:Hemicholinium 3; D001285:Atropine; D000109:Acetylcholine