Neural control of the daily rhythm of sexual behavior in the male golden hamster.
Circadian and neural mechanisms important for the organization of reproductive behavior in the male golden hamster were examined. The sexual behavior of male hamsters exhibits diel variations; males are quicker to initiate copulation and to ejaculate in the dark phase than in the light phase of a daily light-dark cycle. The copulatory rhythm is endogenously generated and persists under constant environmental conditions. Destruction of the suprachiasmatic nuclei (SCN) eliminated the normal diurnal rhythm of sexual behavior without affecting copulation per se. In contrast to SCN lesion effects, damage to the medial preoptic area (MPOA) reduced or eliminated copulation; in those MPOA-ablated animals that continued to copulate, the circadian modulation of sexual behavior remained intact.
D000818:Animals; D001931:Brain Mapping; D002940:Circadian Rhythm; D003307:Copulation / Q000502:physiology; D006224:Cricetinae; D004542:Ejaculation; D008027:Light; D008297:Male; D008647:Mesocricetus; D009434:Neural Pathways / Q000502:physiology; D011301:Preoptic Area / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013493:Suprachiasmatic Nucleus / Q000502:physiology*