Influence of noxious mechanical stimulation of the skin on serotonin release in the central nucleus of the amygdala in rats

Abstract

Noxious mechanical stimulation of the skin increases serotonin (5-HT) release in the central nucleus of the amygdala (CeA) in anesthetized rats. We introduce our recent results on the contribution of corticotropin releasing factor (CRF) receptors in the dorsal raphe nucleus (DRN) to 5-HT release in the CeA in response to noxious cutaneous stimulation. Release of 5-HT in the CeA was monitored by microdialysis before and after 10-min stimulation by pinching. Increased 5-HT release in the CeA in response to pinching was abolished by either non-selective CRF receptor antagonism or selective CRF2 receptor antagonism in the DRN, but not by selective CRF1 receptor antagonism. These results suggest that 5-HT release in the CeA in response to noxious mechanical stimulation of the skin is mediated via the CRF2 receptors in the DRN.