Cullinan W E, Herman J P, Watson S J
Mental Health Research Institute, University of Michigan, Ann Arbor 48109-0720.
J Comp Neurol. 1993 Jun 1;332(1):1-20. doi: 10.1002/cne.903320102.
The axonal projections of the ventral subiculum to the bed nucleus of the stria terminalis (BST) were examined in the rat with the anterograde neuronal tracer Phaseolus vulgaris-leucoagglutinin (PHA-L). Axons originating in the ventral subiculum coursed to the BST through either the fimbria-fornix, or a pathway involving the stria terminalis via the amygdala. Ventral subicular axons gave rise to dense terminal networks that were preferentially distributed in medial and ventral subregions of the BST. The distribution of subicular fibers and terminals was examined in relation to BST neurons that project to the hypothalamic paraventricular nucleus (PVN). In these cases, discrete iontophoretic injections of the retrograde tracer Fluoro-gold were made in the PVN, with PHA-L delivered to the ipsilateral ventral subiculum. An immunocytochemical double-labeling protocol was then employed for the simultaneous detection of PHA-L and Fluoro-gold, and provided light microscopic evidence for subicular input to PVN-projecting cells located within the BST. In a second series of experiments, the gamma-amino butyric acid (GABA)ergic nature of the BST was examined by in situ hybridization histochemistry for detection of transcripts encoding GAD67 mRNA. The studies revealed that a high proportion of BST neurons express GAD67 transcripts. Also, experiments combining Fluoro-gold tracing with GAD67 in situ hybridization suggested that a proportion of PVN-projecting neurons in the BST are GABAergic. Taken together, the results of these sets of studies suggest that the inhibitory influences of the hippocampus on the PVN might be relayed through specific portions of the BST. These findings may have important implications for our understanding of the neural regulation of the hypothalamic-pituitary-adrenal axis.
运用顺行性神经元示踪剂菜豆白细胞凝集素（PHA-L），在大鼠中研究了腹侧下托向终纹床核（BST）的轴突投射。起源于腹侧下托的轴突通过穹窿海马伞，或一条经杏仁核涉及终纹的通路，延伸至BST。腹侧下托轴突形成密集的终末网络，这些网络优先分布于BST的内侧和腹侧亚区。研究了下托纤维和终末的分布与投射至下丘脑室旁核（PVN）的BST神经元的关系。在这些实验中，向PVN进行离散的离子导入逆行示踪剂荧光金注射，并将PHA-L注入同侧腹侧下托。然后采用免疫细胞化学双重标记方案，同时检测PHA-L和荧光金，为下托向位于BST内的投射至PVN的细胞提供了光镜证据。在第二组实验中，通过原位杂交组织化学检测编码GAD67 mRNA的转录本，研究了BST的γ-氨基丁酸（GABA）能性质。研究表明，高比例的BST神经元表达GAD67转录本。此外，将荧光金追踪与GAD67原位杂交相结合的实验表明，BST中一部分投射至PVN的神经元是GABA能的。综上所述，这几组研究结果表明，海马体对PVN的抑制作用可能通过BST的特定部分传递。这些发现可能对我们理解下丘脑-垂体-肾上腺轴的神经调节具有重要意义。
