Tsubouchi Ken, Tsumori Toshiko, Yokota Shigefumi, Okunishi Hideki, Yasui Yukihiko
Department of Anatomy and Morphological Neuroscience, Shimane University School of Medicine, Izumo, Japan.
Neurosci Res. 2007 Dec;59(4):390-8. doi: 10.1016/j.neures.2007.08.010. Epub 2007 Aug 22.
The organization of projections from the central amygdaloid nucleus (CeA) to the paraventricuilar hypothalamic nucleus (PVH) has been studied in order to understand the anatomical substrates of amygdaloid modulation of endocrine and autonomic functions, and a hypothesis that the bed nucleus of the stria terminalis (BST) may act as a relay site between the CeA and PVH has been proposed. Using anterograde and retrograde tract-tracing methods, in the rat, we first indicated that neurons in the parastrial nucleus (PS), where projection fibers from the central amygdaloid nucleus (CeA) terminated, sent their axons to the paraventricular hypothalamic nucleus (PVH). We further demonstrated that the CeA terminals formed symmetrical synaptic contacts with somata and dendrites of the PVH-projecting PS neurons, and that the PS received CeA fibers predominantly from the lateral part and sent large numbers of projection fibers to almost all the subdivisions of the PVH. Using anterograde tracing combined with the postembedding immunogold method, we finally revealed that nearly all the CeA terminals in the PS were immunoreactive for gamma-aminobutyric acid. The present data suggest that output signals from the CeA are transmitted disynaptically to the PVH neurons via the PS neurons and modulate PVH neuron activity by way of disinhibition.
为了了解杏仁核调节内分泌和自主功能的解剖学基础，人们对从中央杏仁核（CeA）到下丘脑室旁核（PVH）的投射组织进行了研究，并提出终纹床核（BST）可能作为CeA和PVH之间的中继位点这一假说。利用顺行和逆行示踪方法，在大鼠中，我们首先表明，来自中央杏仁核（CeA）的投射纤维终止于旁纹核（PS），该核中的神经元将其轴突发送至下丘脑室旁核（PVH）。我们进一步证明，CeA终末与投射至PVH的PS神经元的胞体和树突形成对称突触联系，并且PS主要从外侧部分接收CeA纤维，并向PVH的几乎所有亚区发送大量投射纤维。利用顺行示踪结合包埋后免疫金法，我们最终发现PS中几乎所有的CeA终末对γ-氨基丁酸呈免疫反应性。目前的数据表明，来自CeA的输出信号通过PS神经元双突触传递至PVH神经元，并通过去抑制方式调节PVH神经元的活动。
