Meister B, Hökfelt T, Geffard M, Oertel W
Department of Histology and Neurobiology, Karolinska Institute, Stockholm, Sweden.
Neuroendocrinology. 1988 Nov;48(5):516-26. doi: 10.1159/000125058.
The indirect immunofluorescence technique was used to study the relation between corticotropin-releasing factor (CRF) and GABAergic neurons in the rat hypothalamic paraventricular nucleus (PVN). In colchicine-pretreated animals, glutamic acid decarboxylase (GAD)- and GABA-immunoreactive (IR) neurons were observed within the medial part of the parvocellular division of the PVN as well as surrounding the nucleus itself. In general, the GAD antiserum, as compared to the GABA antiserum, revealed stronger IR cells and a higher number of cells in the PVN. CRF-IR cells were observed throughout the whole rostrocaudal extension of the PVN, but predominantly in its dorsal medial parvocellular part. Adjacent sections stained, respectively, with antisera against CRF, GAD or GABA, revealed overlapping distributional patterns within the parvocellular part of the PVN. Employing a direct double-staining technique with sheep GAD and rabbit CRF antisera, it was demonstrated that both GAD and CRF immunoreactivities occurred in the same neurons, particularly in the dorsomedial aspect of the parvocellular PVN. GAD-positive neurons located in the ventromedial parvocellular PVN, periventricular nucleus and surrounding the PVN lacked CRF immunoreactivity. In addition, with an elution-restaining technique it was possible to demonstrate that also GABA immunoreactivity was present in some CRF neurons in the dorsomedial parvocellular PVN. Intravenous injection of the retrograde tracer Fast Blue resulted in labelling of neurons in the periventricular area and in both the parvocellular and magnocellular division of the PVN. After processing the sections for GAD/CRF immunohistochemistry, it was possible to demonstrate the presence of retrogradely labelled GAD/CRF cells, pointing at a PVN median eminence projection for these neurons. The present findings demonstrate that a subpopulation of the CRF-containing neurons in the parvocellular division of the PVN in addition are GABAergic, thereby indicating a possible corelease of these compounds, presumably in the median eminence. Possible interactions of GABA within the hypothalamo-pituitary-adrenal axis are discussed.
采用间接免疫荧光技术研究促肾上腺皮质激素释放因子（CRF）与大鼠下丘脑室旁核（PVN）中γ-氨基丁酸能神经元之间的关系。在秋水仙碱预处理的动物中，在PVN小细胞部内侧部分以及核本身周围观察到谷氨酸脱羧酶（GAD）和γ-氨基丁酸免疫反应性（IR）神经元。一般来说，与γ-氨基丁酸抗血清相比，GAD抗血清在PVN中显示出更强的IR细胞和更多的细胞数量。在PVN整个 rostrocaudal 延伸范围内均观察到CRF-IR细胞，但主要位于其背内侧小细胞部。分别用抗CRF、GAD或γ-氨基丁酸抗血清染色的相邻切片显示，在PVN小细胞部内存在重叠的分布模式。采用羊GAD和兔CRF抗血清的直接双重染色技术表明，GAD和CRF免疫反应性存在于同一神经元中，特别是在小细胞PVN的背内侧。位于腹内侧小细胞PVN、室周核和PVN周围的GAD阳性神经元缺乏CRF免疫反应性。此外，采用洗脱保留技术可以证明，在背内侧小细胞PVN的一些CRF神经元中也存在γ-氨基丁酸免疫反应性。静脉注射逆行示踪剂快蓝导致室周区域以及PVN小细胞部和大细胞部的神经元被标记。在对切片进行GAD/CRF免疫组织化学处理后，可以证明存在逆行标记的GAD/CRF细胞，表明这些神经元向PVN正中隆起投射。本研究结果表明，PVN小细胞部中含CRF的神经元亚群此外还是γ-氨基丁酸能的，从而表明这些化合物可能在正中隆起共同释放。讨论了γ-氨基丁酸在下丘脑-垂体-肾上腺轴内可能的相互作用。
