Role of serotonin in the amygdala in hypothalamo-pituitary-adrenocortical responses.
In view of the fact that the amygdala (AMG) and hypothalamic serotonin (5-HT) have an excitatory effect on the hypothalamo-pituitary-adrenal (HPA) axis, we have investigated the role of 5-HT in the AMG on this response. In intact freely moving rats, a mildly stressing short photic stimulation caused depletion of median eminence CRH-41, due to its release into the portal circulation and a rise in serum ACTH and corticosterone levels. This effect was significantly inhibited in rats in which 5-HT was depleted in the AMG following local 5,7-dihydroxytryptamine administration, which did not affect hypothalamic 5-HT content. Also, local pretreatment with ketanserin (a 5-HT2 receptor antagonist) in the AMG had the same inhibitory effect on the HPA axis response. These results indicate that AMG 5-HT has an important role in the activation of the HPA axis following neural stimulation and that 5-HT2 receptors are involved.
Department of Neurology, Hadassah University Hospital and Hebrew University, Hadassah Medical School, Jerusalem, Israel.
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S
Feldman
M E
ME
Newman
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E
Gur
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J
Weidenfeld
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000679:Amygdala / Q000502:physiology*; D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000097:blood; D004567:Electrodes, Implanted; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology*; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D010913:Pituitary-Adrenal System / Q000502:physiology*; D051381:Rats; D012701:Serotonin / Q000502:physiology*; D018490:Serotonin Agents / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology
D018490:Serotonin Agents; D012702:Serotonin Antagonists; D015116:5,7-Dihydroxytryptamine; D012701:Serotonin; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D007650:Ketanserin