Effects of continuous light and darkness, and of pinealectomy, adrenalectomy and gonadectomy on uptake of 3H-serotonin by the suprachiasmatic nuclear region of male rats.
Rats exposed to continuous light show no significant differences in serotonin (5-HT) uptake by the suprachiasmatic nuclear region (SNR) at 10.00 and 22.00 L, while in continuous darkness, the uptake at 10.00 D is significantly higher than uptake at 22.00 D. In consideration of the role of the suprachiasmatic nucleus in light-mediated control of neuroendocrine activity, this suggests endogenous generation or control of this uptake rhythm. An effect of sham-pinealectomy in decreasing 5-HT uptake was found, but cannot be fully interpreted at this time. The lack of effect of castration or adrenalectomy suggests that these endocrines have little if any direct effect on 5-HT mechanisms in the SNR.
D000315:Adrenalectomy; D000818:Animals; D002369:Castration; D002940:Circadian Rhythm; D003624:Darkness; D007031:Hypothalamus / Q000378:metabolism*; D008027:Light; D008297:Male; D010870:Pineal Gland / Q000502:physiology; D051381:Rats; D012701:Serotonin / Q000378:metabolism*
D012701:Serotonin