title: Effects of diazepam on circadian phase advances and delays.
abstract: Phase advances of hamster locomotor rhythms, which normally can be induced by light pulses in the late subjective night, were blocked in a dose-dependent manner by the benzodiazepine, diazepam. Light-induced phase delays were unaffected at doses that significantly blocked phase advances. Diazepam caused small phase delays of the free-running rhythm when given without a light pulse at either phase advance or phase delay time points. These results are discussed with regard to the possibility that different neurochemical mechanisms are required to process light-induced phase advances and delays and that GABA neurotransmission may be involved in the modulation of light input to the clock.
mesh_terms: D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D002940:Circadian Rhythm / Q000187:drug effects*; D006224:Cricetinae; D003975:Diazepam / Q000494:pharmacology*; D008027:Light; D008297:Male; D008647:Mesocricetus; D009043:Motor Activity / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects; D005680:gamma-Aminobutyric Acid / Q000502:physiology
chemical_list: D005680:gamma-Aminobutyric Acid; D003975:Diazepam; D001640:Bicuculline