Weidenfeld Joseph, Newman Michael E, Itzik Anna, Gur Eitan, Feldman Shaul
Department of Neurology, Agnes Ginges Center for Human Neurogenetics, Hadassah University Hospital and Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Neuroendocrinology. 2002 Aug;76(2):63-9. doi: 10.1159/000064430.
The amygdala is known to modulate the function of the hypothalamo-pituitary-adrenocortical (HPA) axis, but the mechanism of this effect is still not clear. In the present study we examined the specific role of the serotonin (5-HT) system in mediating the effect of the amygdala on the activity of the HPA axis. Bilateral lesions of the amygdala in rats reduced the adrenocorticotropin (ACTH) and corticosterone responses to electrical stimulation of the dorsal raphe nucleus, where the cell bodies of serotonergic neurons are located. Amygdala lesions had no effect on the ACTH and corticosterone responses to administration of a 5-HT(1A) receptor agonist directly into the paraventricular nucleus (PVN) of the hypothalamus, indicating that there was no impairment in the activity of postsynaptic 5-HT(1A) receptors in the hypothalamus. In vivo microdialysis showed that amygdala lesions markedly attenuated the effect of electrical stimulation of the dorsal raphe to increase extracellular secretion of 5-HT in the PVN. This is the first demonstration that the amygdala has a facilitatory effect on the function of dorsal raphe 5-HT neurons which project to the PVN, and suggests a mechanism by which the amygdala may modulate the function of the HPA axis.
已知杏仁核可调节下丘脑 - 垂体 - 肾上腺皮质（HPA）轴的功能，但其作用机制仍不清楚。在本研究中，我们研究了血清素（5 - HT）系统在介导杏仁核对HPA轴活性影响中的具体作用。大鼠双侧杏仁核损伤降低了促肾上腺皮质激素（ACTH）和皮质酮对位于中缝背核（血清素能神经元胞体所在部位）电刺激的反应。杏仁核损伤对直接向下丘脑室旁核（PVN）注射5 - HT（1A）受体激动剂后的ACTH和皮质酮反应没有影响，这表明下丘脑突触后5 - HT（1A）受体的活性没有受损。体内微透析显示，杏仁核损伤显著减弱了中缝背核电刺激增加PVN中5 - HT细胞外分泌的作用。这首次证明杏仁核对投射到PVN的中缝背核5 - HT神经元的功能具有促进作用，并提示了杏仁核可能调节HPA轴功能的一种机制。
