CONTRIBUTION OF THE VENTRAL SUBICULUM TO INHIBITORY REGULATION OF THE HYPOTHALAMO-PITUITARY-ADRENOCORTICAL AXIS
CONTRIBUTION OF THE VENTRAL SUBICULUM TO INHIBITORY REGULATION OF THE HYPOTHALAMO-PITUITARY-ADRENOCORTICAL AXIS
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DOI：
10.1111/j.1365-2826.1995.tb00784.x
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发表时间：
1995-06-01
影响因子：
3.2
通讯作者：
WATSON, SJ
中科院分区：
文献类型：
--
作者：
HERMAN, JP;CULLINAN, WE;WATSON, SJ
解剖学研究表明，腹侧小脑处于重要位置，介导了海马对下丘脑-垂体-肾上腺皮质(HPA)轴的抑制。本研究通过评估鹅掌酸损毁腹侧下丘脑区后的HPA功能来评估这一假说。与假损毁大鼠(Sham)或未手术对照组相比，损毁腹侧下丘脑核(VSUB)或腹侧海马区(VHIPPO)的大鼠在昼夜节律高峰或谷底时间点的基础皮质酮(Cort)分泌均无变化。然而，与所有其他组相比，vSUB损伤的大鼠表现出更长的糖皮质激素应激反应。与对照组相比，vSUB组小细胞侧室旁核(PVN)内侧室旁核(PVN)CRH mRNA表达水平显著升高，尤其是尾侧水平，提示vSUB与PVN神经元的相互作用具有局部组织性。值得注意的是，vHIPPO组接受了腹侧CA1、CA3和齿状回的大损伤，但没有明显的皮质下损伤，在应激诱导的皮质醇分泌方面没有变化，这表明腹侧下丘本身在HPA应激反应中主要负责腹侧海马区的作用。VSUB组和vHIPPO组小细胞内侧室旁核AVP基因表达无明显差异。结果表明，腹侧下托对HPA的激活有特异性的抑制作用。在基础皮质醇分泌或AVP mRNA表达没有改变的情况下，CRH生物合成和应激诱导的皮质醇分泌增加，表明腹侧下丘脑神经元的抑制作用影响了HPA轴的反应能力。
Anatomical studies indicate that the ventral subiculum is in a prime position to mediate hippocampal inhibition of the hypothalamo-pituitary-adrenocortical (HPA) axis. The present study evaluated this hypothesis by assessing HPA function following ibotenic acid lesion of the ventral subiculum region. Rats with lesions of the ventral subiculum (vSUB) or ventral hippocampus (vHIPPO) did not show changes in basal corticosterone (CORT) secretion at either circadian peak or nadir time points when compared to sham-lesion rats (SHAM) or unoperated controls. However, rats with vSUB lesions exhibited a prolonged glucocorticoid stress response relative to all other groups. Baseline CRH mRNA levels were significantly increased in the medial parvocellular paraventricular nucleus (PVN) of the vSUB group relative to controls, CRH mRNA differences were particularly pronounced at caudal levels of the nucleus, suggesting topographic organization of vSUB interactions with PVN neurons. Notably, the vHIPPO group, which received large lesions of ventral CA1, CA3 and dentate gyrus without significant subicular damage, showed no change in stress-induced CORT secretion, suggesting that the ventral subiculum proper is principally responsible for ventral hippocampal actions on the HPA stress response. No differences in medial parvocellular PVN AVP mRNA expression were seen in either the vSUB or vHIPPO groups. The results indicate a specific inhibitory action of the ventral subiculum on HPA activation. The increase in CRH biosynthesis and stress-induced CORT secretion in the absence of changes in baseline CORT secretion or AVP mRNA expression suggests that the inhibitory actions of ventral subicular neurons affect the response capacity of the HPA axis.