Facultat de Ciències Biològiques, Laboratory of Functional and Comparative Neuroanatomy, Departament de Biologia Cel·lular, Universitat de València València, Spain.
Front Neuroanat. 2012 Aug 21;6:33. doi: 10.3389/fnana.2012.00033. eCollection 2012.
The medial amygdaloid nucleus (Me) is a key structure in the control of sociosexual behavior in mice. It receives direct projections from the main and accessory olfactory bulbs (AOB), as well as an important hormonal input. To better understand its behavioral role, in this work we investigate the structures receiving information from the Me, by analysing the efferent projections from its anterior (MeA), posterodorsal (MePD) and posteroventral (MePV) subdivisions, using anterograde neuronal tracing with biotinylated and tetrametylrhodamine-conjugated dextranamines. The Me is strongly interconnected with the rest of the chemosensory amygdala, but shows only moderate projections to the central nucleus and light projections to the associative nuclei of the basolateral amygdaloid complex. In addition, the MeA originates a strong feedback projection to the deep mitral cell layer of the AOB, whereas the MePV projects to its granule cell layer. The Me (especially the MeA) has also moderate projections to different olfactory structures, including the piriform cortex (Pir). The densest outputs of the Me target the bed nucleus of the stria terminalis (BST) and the hypothalamus. The MeA and MePV project to key structures of the circuit involved in the defensive response against predators (medial posterointermediate BST, anterior hypothalamic area, dorsomedial aspect of the ventromedial hypothalamic nucleus), although less dense projections also innervate reproductive-related nuclei. In contrast, the MePD projects mainly to structures that control reproductive behaviors [medial posteromedial BST, medial preoptic nucleus, and ventrolateral aspect of the ventromedial hypothalamic nucleus], although less dense projections to defensive-related nuclei also exist. These results confirm and extend previous results in other rodents and suggest that the medial amygdala is anatomically and functionally compartmentalized.
内侧杏仁核（Me）是控制小鼠社交性行为的关键结构。它接收来自主嗅球和副嗅球（AOB）的直接投射，以及重要的激素输入。为了更好地了解其行为作用，在这项工作中，我们通过使用生物素化和四甲基罗丹明缀合的葡聚糖胺进行顺行神经元追踪，分析其前（MeA）、后背（MePD）和后腹（MePV）亚区的传出投射，来研究接收来自 Me 的信息的结构。Me 与化学感觉杏仁核的其余部分紧密相连，但仅向中央核发出中度投射，向基底外侧杏仁核复合体的联合核发出轻度投射。此外，MeA 起源于对 AOB 深嗅小球层的强烈反馈投射，而 MePV 投射到其颗粒细胞层。Me（尤其是 MeA）还对包括梨状皮层（Pir）在内的不同嗅觉结构具有中度投射。Me 的最密集输出目标是终纹床核（BST）和下丘脑。MeA 和 MePV 投射到参与防御反应的关键结构，包括对捕食者的防御反应（中后内侧 BST、下丘脑前区、腹内侧下丘脑核的背侧部分），尽管投射到生殖相关核的密度较低。相比之下，MePD 主要投射到控制生殖行为的结构[中后内侧 BST、内侧视前核和腹内侧下丘脑核的腹外侧部分]，尽管存在密度较低的投射到防御相关核。这些结果证实并扩展了其他啮齿动物的先前结果，并表明内侧杏仁核在解剖和功能上是分区的。
