Sun N, Cassell M D
Department of Anatomy, University of Iowa College of Medicine, Iowa City 52242.
J Comp Neurol. 1993 Apr 15;330(3):381-404. doi: 10.1002/cne.903300308.
The present study examined the distribution, morphology, and connections of gamma-aminobutyric acid-immunoreactive (GABA-IR) neurons in the three principal components of the central extended amygdala: the central amygdaloid nucleus, the bed nucleus of the stria terminalis (BNST) and the sublenticular substantia innominata. In the central nucleus, large numbers of GABA-IR neurons were identified in the lateral, lateral capsular, and ventral subdivisions, though in the medial subdivision, GABA-IR neurons were only present at very caudal levels. Combined immunocytochemistry-Golgi impregnation revealed that GABA-IR neurons in the lateral central nucleus were medium-sized spiny neurons that were morphologically similar to GABAergic neurons in the striatum. Injections of horseradish peroxidase into the bed nucleus of the stria terminalis labeled a major proportion of the GABA-IR neurons in the central nucleus. In the bed nucleus, the majority of GABA-IR neurons were located in the anterolateral subdivision, ventral part of the posterolateral subdivision and the parastrial subdivision. GABA-IR neurons in the anterolateral bed nucleus were of the typical medium-sized spiny type. Injections of horseradish peroxidase into the central nucleus labeled a few GABA-IR neurons in the posterior part of the anterolateral bed nucleus. GABA-IR neurons were identified in the sublenticular substantia innominata and medial shell of the nucleus accumbens and contributed to the continuum of GABA-IR extending from the central nucleus to the bed nucleus. Injections of horseradish peroxidase (HRP) into the central nucleus, but not the BNST, labeled a few GABA-IR neurons in the substantia innominata. The data point to GABA-IR neurons being a characteristic feature of the central extended amygdala and that GABA-IR neurons participate in the long intrinsic connections linking the major components of this structure. Since lesions of the stria terminalis and basolateral amygdaloid nucleus failed to deplete GABA-IR terminals in the central nucleus, the role of GABA in local and short intrinsic connections in the central extended amygdala is discussed. Further, physiological findings implicating the intrinsic GABAergic system of the central extended amygdala in the tonic inhibition of brainstem efferents are reviewed.
本研究考察了中央杏仁核扩展部三个主要组成部分中γ-氨基丁酸免疫反应性（GABA-IR）神经元的分布、形态及连接情况，这三个主要组成部分为：中央杏仁核、终纹床核（BNST）和豆状核下无名质。在中央核中，外侧、外侧囊及腹侧亚区发现了大量GABA-IR神经元，而在内侧亚区，仅在非常靠尾端的水平存在GABA-IR神经元。联合免疫细胞化学-高尔基染色显示，外侧中央核中的GABA-IR神经元为中等大小的棘状神经元，其形态与纹状体中的GABA能神经元相似。向终纹床核注射辣根过氧化物酶标记了中央核中大部分GABA-IR神经元。在终纹床核中，大多数GABA-IR神经元位于前外侧亚区、后外侧亚区腹侧部分及终纹旁亚区。前外侧终纹床核中的GABA-IR神经元为典型的中等大小棘状类型。向中央核注射辣根过氧化物酶标记了前外侧终纹床核后部的少数GABA-IR神经元。在豆状核下无名质及伏隔核内侧壳中鉴定出了GABA-IR神经元，它们构成了从中央核延伸至终纹床核的GABA-IR连续区域。向中央核而非BNST注射辣根过氧化物酶（HRP）标记了无名质中的少数GABA-IR神经元。这些数据表明GABA-IR神经元是中央杏仁核扩展部的一个特征性标志，且GABA-IR神经元参与了连接该结构主要组成部分的长距离内在连接。由于终纹和基底外侧杏仁核损伤未能使中央核中的GABA-IR终末减少，因此讨论了GABA在中央杏仁核扩展部局部及短距离内在连接中的作用。此外，还综述了有关中央杏仁核扩展部内在GABA能系统对脑干传出纤维进行紧张性抑制的生理学研究结果。
