Kemppainen S, Pitkänen A
A.I. Virtanen Institute for Molecular Sciences, University of Kuopio, FIN-70211 Kuopio, Finland.
J Comp Neurol. 2000 Oct 23;426(3):441-67. doi: 10.1002/1096-9861(20001023)426:3<441::aid-cne8>3.0.co;2-7.
To understand the organization of inhibitory circuitries in the rat amygdala, the distribution of parvalbumin, calretinin, and calbindin immunoreactivity was investigated in the rat amygdaloid complex. Colocalization of various calcium-binding proteins with the inhibitory transmitter gamma-aminobutyric acid (GABA) was studied by using the mirror technique. Parvalbumin-immunoreactive (-ir) elements were located mostly in the deep amygdaloid nuclei, whereas the calretinin-ir and calbindin-ir staining were most intense in the cortical nuclei as well as in the central nucleus and the amygdalohippocampal area. Second, the distribution of immunopositive neurons largely parallelled the distribution of terminal and neuropil labeling. Third, immunostained neurons could be divided into four major morphologic types (types 1-4) based on the characteristics of the somata and the dendritic trees. The fourth lightly stained neuronal type that had a pyramidal GABA-negative soma was observed only in calretinin and calbindin preparations. Fourth, parvalbumin-ir terminals formed basket-like plexus and cartridges, which suggests that parvalbumin labels GABAergic inhibitory basket cells and axo-axonic chandelier cells, respectively. Colocalization studies indicated that 521 of 553 (94%) of parvalbumin-ir, 419 of 557 (75%) of calbindin-ir, and 158 of 657 (24%) of calretinin-ir neurons were GABA-positive in the deep amygdaloid nuclei. A high density of large GABA-negative calbindin-ir neurons was observed caudally in the medial division of the lateral nucleus and GABA-negative calretinin-ir neurons were observed in the magnocellular division of the accessory basal nucleus as well as in the intermediate and parvicellular divisions of the basal nucleus. These data suggest that in various amygdaloid areas, neuronal excitability is controlled by GABAergic neurons that contain different calcium-binding proteins. The appearance of basket-like plexus and cartridges in the parvalbumin preparations, but not in calretinin preparations, suggests that like in the hippocampus, the distribution of inhibitory terminals in the dendritic and perisomatic regions of postsynaptic neurons in the rat amygdala is organized in a topographic manner.
为了解大鼠杏仁核中抑制性神经回路的组织情况，研究了大鼠杏仁核复合体中小清蛋白、钙视网膜蛋白和钙结合蛋白免疫反应性的分布。采用镜像技术研究了各种钙结合蛋白与抑制性递质γ-氨基丁酸（GABA）的共定位。小清蛋白免疫反应性（-ir）元件主要位于杏仁核深部核团，而钙视网膜蛋白-ir和钙结合蛋白-ir染色在皮质核团、中央核团及杏仁海马区最为强烈。其次，免疫阳性神经元的分布在很大程度上与终末和神经毡标记的分布平行。第三，根据胞体和树突的特征，免疫染色的神经元可分为四种主要形态类型（1-4型）。仅在钙视网膜蛋白和钙结合蛋白制剂中观察到第四种轻度染色的神经元类型，其具有锥形的GABA阴性胞体。第四，小清蛋白-ir终末形成篮状丛和小体，这表明小清蛋白分别标记了GABA能抑制性篮状细胞和轴-轴突吊灯细胞。共定位研究表明，在杏仁核深部核团中，553个小清蛋白-ir神经元中有521个（94%）、557个钙结合蛋白-ir神经元中有419个（75%）、657个钙视网膜蛋白-ir神经元中有158个（24%）为GABA阳性。在外侧核内侧部尾侧观察到高密度的大的GABA阴性钙结合蛋白-ir神经元，在副基底核大细胞部以及基底核中间部和小细胞部观察到GABA阴性钙视网膜蛋白-ir神经元。这些数据表明，在不同的杏仁核区域，神经元兴奋性由含有不同钙结合蛋白的GABA能神经元控制。小清蛋白制剂中出现篮状丛和小体，而钙视网膜蛋白制剂中未出现，这表明与海马体一样，大鼠杏仁核中突触后神经元树突和胞体周围区域的抑制性终末分布呈拓扑学方式组织。
