Posterior hypothalamic deafferentation or 5,7-dihydroxytryptamine inhibit corticotropin-releasing hormone, ACTH and corticosterone responses following photic stimulation.
The effect of posterior hypothalamic deafferentation (PHD) or hypothalamic serotonin (5-HT) depletion by 5,7-dihydroxytryptamine on corticotropin-releasing hormone (CRH), ACTH and corticosterone (CS) responses, following photic stimulation, was investigated in male rats. In intact animals, photic stimulation caused median eminence (ME) CRH depletion and a rise in serum ACTH and CS levels. In rats with PHD, in which previous studies have demonstrated 5-HT depletion, or with neurotoxin induced hypothalamic 5-HT reduction, these responses were markedly inhibited. This indicates that the blockage in the release of ME CRH into the portal circulation in rats with hypothalamic 5-HT depletion is responsible for the inhibition of the pituitary-adrenocortical responses following photic stimulation.
Feldman
S
S
Department of Neurology, Hadassah University Hospital, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Weidenfeld
J
J
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology*; D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000818:Animals; D003345:Corticosterone / Q000097:blood*; D003346:Corticotropin-Releasing Hormone / Q000097:blood*; D003714:Denervation; D003864:Depression, Chemical; D007034:Hypothalamus, Posterior / Q000166:cytology / Q000502:physiology*; D008297:Male; D009475:Neurons, Afferent / Q000502:physiology; D010775:Photic Stimulation; D011903:Raphe Nuclei / Q000166:cytology / Q000502:physiology; D051381:Rats; D018490:Serotonin Agents / Q000494:pharmacology*
D018490:Serotonin Agents; D015116:5,7-Dihydroxytryptamine; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D003345:Corticosterone