Local origins of some GABAergic projections to the paraventricular and supraoptic nuclei of the hypothalamus in the rat.
Local origins of some GABAergic projections to the paraventricular and supraoptic nuclei of the hypothalamus in the rat.
复制标题
大鼠下丘脑室旁核和视上核的一些 GABA 能投射的局部起源。
DOI：
10.1002/cne.903320109
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Sawchenko,PE
中科院分区：
文献类型：
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作者：
Roland,BL;Sawchenko,PE
采用轴突运输和免疫组织化学方法表征大鼠下丘脑室旁核（PVH）和视上核（SO）谷氨酸脱羧酶免疫反应（GAD-ir）投射的组织结构。与之前的报告一致，发现GAD-ir静脉曲张密集且相当均匀地分布在整个下丘脑，包括PVH和SO。尽管如此，PVH的脑室周围部分始终被发现含有不成比例的高密度GAD-ir元素。将逆行示踪剂（真蓝）的小晶体植入前穹窿周围区、下丘脑前区紧邻PVH腹侧的部分、吻侧SO背侧的区域并向尾内侧延伸至视交叉和视束，以及PVH本身的前三分之一内的PVH标记GAD-ir细胞中。由于局部树突状突起可能摄取逆行示踪剂可能导致附近GAD-ir细胞的假阳性填充，因此使用顺行转运、菜豆-白细胞凝集素和联合顺行转运-免疫组织化学方法试图确认这四种假定的GAD-ir输入的局部来源。示踪剂注射在每个上述区域标记稀疏到中度轴突投影PVH，其中分歧优先在小细胞分裂的核。在该材料中，PVH和SO的大细胞分裂的投影通常稀疏且不一致。PVH中顺行标记的轴突和终末的可变且通常较小的比例也显示GAD-ir。这些结果表明，GABA能预测内脏细胞类型的PVH和SO出现，至少部分，从几个弥漫性分布的本地来源。事实上，这些传入被发现优先终止于PVH的小细胞分裂，使得它可能是GABA能投射到大细胞神经分泌系统的其他来源仍有待确定。核周和核内GABA能神经元可以提供一种中介，通过这种中介，边缘系统对神经内分泌功能的影响被证实（通常是抑制性的）。© 1993 Wiley‐利斯公司
Axonal transport and immunohistochemical methods were used to characterize the organization of glutamic acid decarboxylase‐immunoreactive (GAD‐ir) projections to the paraventricular (PVH) and supraoptic (SO) nuclei of the hypothalamus in the rat. In line with prior reports, GAD‐ir varicosities were found to be densely and quite uniformly distributed throughout the hypothalamus, including the PVH and the SO. Nonetheless, the periventricular part of the PVH was consistently found to contain a disproportionately high density of GAD‐ir elements. Small crystalline implants of the retrograde tracer, true blue, into the PVH labeled GAD‐ir cells in the anterior perifornical region, portions of the anterior hypothalamic area immediately ventral to the PVH, a region just dorsal to the rostral SO and extending caudomedially over the optic chiasm and tract, and within the anterior one‐third of the PVH itself. Because possible uptake of retrograde tracer by local dendritic processes might have yielded false positive filling of nearby GAD‐ir cells, anterograde transport,Phaseolus vulgaris‐leucoagglutinin, and combined anterograde transport‐immunohistochemical methods were used to attempt to confirm these four putative local sources of GAD‐ir inputs. Tracer injections in each of the above mentioned regions labeled sparse to moderate axonal projections to the PVH, which ramified preferentially in the parvicellular division of the nucleus. Projections to the magnocellular division of the PVH and the SO were generally sparse and inconsistently observed in this material. A variable, and generally small, proportion of anterogradely labeled axons and terminals in the PVH also displayed GAD‐ir. These results suggest that GABAergic projections to visceromotor cell types in the PVH and SO arise, at least in part, from several diffusely distributed local sources. The fact that these afferents were found to terminate preferentially in the parvicellular division of the PVH makes it likely that additional sources of GABAergic projections to the magnocellular neurosecretory system remain to be identified. Peri‐ and intranuclear GABAergic neurons could provide an intermediary by which documented (and generally inhibitory) limbic system influences on neuroendocrine function are exerted. © 1993 Wiley‐Liss, Inc.