Interrelationship between the cortical and amygdaloid outputs within the forebrain region in the control of the autonomic function.

我们用顺行和逆行相结合的方法显示了从边缘下皮质(ILC)、岛叶皮质(IC)和杏仁中央核(Ac)经由下丘脑外侧核(LH)到达孤束核(NST)的可能通路。这些皮质或杏仁核纤维与NST投射神经元的重叠分布主要分布在LH后的近后部。在该区域，两种皮质纤维与NST投射神经元的树突和棘突形成非对称性突触，而杏仁核纤维与NST投射神经元的树突和细胞体形成对称性突触。我们还用双顺行标记显示了来自IC和ACE的纤维之间以及来自LH神经元之间的突触组织。IC和ACEs纤维的重叠分布主要分布在LH后的近外侧。在这一区域，一些单一的树突或棘突接受来自两组终末的会聚突触输入。用顺行示踪和免疫组织化学相结合的方法，我们进一步证明杏仁核纤维大部分是GABA能的，它们不仅含有透明的小泡，还含有致密的核心小泡，这表明GABA和多肽是共存的。综上所述，这些结果提示了ILC、IC和ACE3种神经通路可能通过黄体生成素到达NST。此外，来自ILC和IC的兴奋性输入和来自Ace的抑制性输入可能整合在LHNST投射神经元中，以控制自主神经功能。

We demonstrated possible pathways from the infralimbic cortex(ILC), the insular cortex(IC) and the central nucleus of the amygdala(ACe), to the nucleus of the solitary tract(NST) via the lateral hypothalamus(LH) using combined anterograde and retrograde tracing method. Prominent overlapping distributions of these cortical or amygdaloid fibers and NST-projecting neurons were observed in the lateralmost part of the posterior LH. In this region, both cortical fibers formed asymmetrical synapses with dendrites and spines of the NST-projecting neurons, whereas the amygdaloid fibers made symmetrical synapses with dendrites and cell bodies of the NST-projecting neurons. We also revealed the synaptic organization between and among the fibers originating from the IC and ACe, and the LH neurons using double anterograde labeling. Prominent overlapping distributions of the IC and ACe fibers were found in the lateralmost part of the posterior LH. In this area, some of single dendrite or spine received convergent synaptic inputs from both sets of terminals. Using anterograde tracing combined with immunohistochemistry for GABA, we further showed that most of the amygdaloid fibers were GABAergic and that they contained not only clear vesicles but also dense-cored vesicles, suggesting the co-localization of GABA and peptides. Taken together, these results suggest possible pathways from the ILC, IC and ACe to the NST via the LH. Moreover, excitatory inputs from the ILC and IC, and inhibitory inputs from the Ace might be integrated in the NST-projecting neurons in the LH for the control of the autonomic function