Suprachiasmatic nucleus and photoperiodic regulation of gonadal development in the Siberian hamster, Phodopus sungorus.
Photoregressed Siberian hamsters exposed at 19 days of age to constant light for 24 h manifested increased testicular development 16 days later. Hamsters that sustained lesions of the suprachiasmatic nucleus (SCN) 3 days after the light pulse had significantly heavier gonads than did sham-operated animals or hamsters pinealectomized at 19 days of age. Enhanced reproductive development after SCN ablation is not due solely to lesion-induced elimination of melatonin secretion. SCN neural activity beginning 3 days after the light pulse is not necessary for light-induced gonadal growth.
Kelly
K K
KK
Department of Psychology, University of California, Berkeley 94720, USA.
Dark
J
J
Zucker
I
I
D000818:Animals; D001835:Body Weight / Q000502:physiology; D006224:Cricetinae; D005260:Female; D008297:Male; D009897:Optic Chiasm / Q000502:physiology; D009929:Organ Size / Q000502:physiology; D010286:Paraventricular Hypothalamic Nucleus / Q000502:physiology; D017111:Phodopus; D017440:Photoperiod; D010870:Pineal Gland / Q000502:physiology; D011247:Pregnancy; D013493:Suprachiasmatic Nucleus / Q000502:physiology*; D013737:Testis / Q000254:growth & development* / Q000502:physiology