An NK1 receptor antagonist affects the circadian regulation of locomotor activity in golden hamsters.

摘要: Substance P (SP) is a neuromodulator which may participate in the photic regulation of circadian timing system mammals. The biological effects SP are mediated by interaction with specific receptors, designated as NK1, NK2, and NK3. NK1 subtype receptor expressed system. Experiment 1 was designed to test whether an antagonist mimics dark pulses. Hamsters were housed constant lighting conditions, either darkness or light (around 250 lx), they received i.p. injection antagonist, L-760,735 (5 mg/kg), saline during mid-subjective day, time when pulses cause phase-advance rhythm locomotor activity. After treatment significant phase-advances wheel-running activity found light, but not darkness. 2 ability block phase-delaying and/or phase-advancing animals kept Phase-advances that can normally be induced given late subjective night markedly reduced pre-treatment antagonist. By contrast, phase-delays lights early unaffected These data support hypothesis within may, interacting modulate responses SCN pacemaker.