Cullinan W E, Helmreich D L, Watson S J
Mental Health Research Institute, University of Michigan, Ann Arbor 48109-0720, USA.
J Comp Neurol. 1996 Apr 22;368(1):88-99. doi: 10.1002/(SICI)1096-9861(19960422)368:1<88::AID-CNE6>3.0.CO;2-G.
The paraventricular nucleus of the hypothalamus (PVN) serves as the origin of the final common pathway in the secretion of glucocorticoid hormones in response to stress. Various stress-related inputs converge upon the cells of the medial parvocellular division of the PVN. These neurons, which synthesize and release corticotropin-releasing hormone, arginine vasopressin, and other secretagogues, are responsible for a cascade of events which culminates in the adrenocorticotropin-induced release of corticosteroids from the adrenal cortex. Previous data have suggested complex afferent regulation of PVN neurons, although the neuronal pathways by which the effects of stress are mediated remain to be fully disclosed. The present experiment sought to identify forebrain areas potentially involved in afferent regulation of the PVN in response to an acute stressor. Discrete injections of the retrograde tracer Fluoro-gold were delivered to the PVN, and rats were subsequently subjected to an acute swim stress. Brains were processed immunocytochemically for the simultaneous detection of the tracer and Fos, the protein product of the immediate early gene c-fos, utilized as a marker for neuronal activation. The majority of Fluoro-gold/Fos labeled neurons were detected in the parastrial nucleus, the medial preoptic area, the anterior hypothalamic area, the dorsomedial hypothalamic nucleus and adjacent posterior hypothalamic area, and, to a lesser extent, the supramammillary nucleus. These findings are discussed in relation to neural pathways mediating activation and inhibition of the hypothalamic-pituitary-adrenocortical axis.
下丘脑室旁核（PVN）是应激反应中糖皮质激素分泌最终共同通路的起源。各种与应激相关的传入神经汇聚于PVN内侧小细胞部的细胞。这些合成并释放促肾上腺皮质激素释放激素、精氨酸血管加压素及其他促分泌素的神经元，引发了一系列最终导致肾上腺皮质在促肾上腺皮质激素作用下释放皮质类固醇的事件。以往数据提示PVN神经元存在复杂的传入调节，尽管应激效应所介导的神经通路仍有待充分揭示。本实验旨在确定在急性应激源作用下可能参与PVN传入调节的前脑区域。将逆行示踪剂荧光金离散注射到PVN，随后对大鼠施加急性游泳应激。对大脑进行免疫细胞化学处理，以同时检测示踪剂和Fos（即刻早期基因c-fos的蛋白质产物，用作神经元激活的标志物）。大多数荧光金/Fos标记神经元见于终纹旁核、内侧视前区、下丘脑前区、下丘脑背内侧核及相邻的下丘脑后区，在较小程度上还见于乳头体上核。结合介导下丘脑-垂体-肾上腺皮质轴激活和抑制的神经通路对这些发现进行了讨论。
