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目的 探讨甘氨酸能神经元 (Gly- ir)在大脑皮层内的分布及特征。 方法 用免疫组织化学与免疫电镜方法 ,在光镜与电镜水平观察甘氨酸免疫反应性神经元在大鼠运动皮层内的分布及其超微结构特征。 结果 甘氨酸免疫反应性神经元均为非锥体细胞 ,在运动皮层内 ～ 层均有分布 ,以 ～ 层较多 , 层最少 ,免疫反应性细胞以小细胞 (41.5 % )及中等大小细胞 (44 % )为主 ,也可见少量梭形细胞 (13.5 % ) ,而大细胞极少 (1% )。这些不同形态与大小的细胞也有层次分布的特征 : 、 层以小细胞为主 ,而 ～ 、 层则以中等大小细胞为主。电镜下 ,甘氨酸免疫反应性神经元呈现中间神经元的特征 :胞体小、核大浆少、核内陷。胞体上既可见具有扁平或多形囊泡的终末形成的对称型突触 (79.7% ) ,也可见含球形、清亮囊泡的终末形成的非对称型突触 (2 0 .3% )。它的树突上也可见这两种突触类型 ,近端树突上与胞体相似 ,以对称型突触为主 ;而远端细小树突 (直径 <1μm)上则以非对称型突触为主 ;呈现树突越细 ,非对称型突触越多 ,而对称型突触越少的特征。在运动皮层内未能找到 Gly免疫反应性终末分布。 结论 首次观察到大脑运动皮层内确实存在甘氨酸能神经元 ,但目前尚不能肯定甘氨酸在皮层内是否具有神经递质的作用 ,
Objective To investigate the distribution and characteristics of Gly-ir neurons in the cerebral cortex. Methods Immunohistochemistry and immunoelectron microscopy were used to observe the distribution and ultrastructure of glycine immunoreactive neurons in rat motor cortex at light and electron microscopy. Results The immunoreactive neurons of glycine were all non-pyramidal cells distributed in the inner layer of the motor cortex with more layers and the least layer of immunoreactive neurons. Small cells (41.5%) and medium size cells %), But also a small amount of spindle cells (13.5%), while very few large cells (1%). These different shapes and sizes of cells also have the characteristics of the level of distribution: the main layer of small cells, and ~, the layers are mainly medium-sized cells. Under electron microscope, glycine immunoreactive neurons showed the characteristics of interneurons: small cell body, less nuclear plasma and nuclear invagination. Symmetrical synapses (79.7%) with terminal or flattened vesicles with pleomorphic vesicles were visible on the cell body, and terminal asymmetric synapses (20.3%) formed by globular, clear vesicles were also seen . Its dendrites are also visible on both types of synapses, the proximal dendrites and cell body similar to symmetrical synapses based; and distal small dendrites (diameter <1μm) on the asymmetric synapses Mainly showed the more dendritic, more asymmetric synapses, while the less symmetrical synapses. No Gly-immunoreactive terminal distribution was found in the motor cortex. Conclusions For the first time, glycine-ergic neurons are indeed found in the motor cortex of the brain. However, it is uncertain whether glycine has a neurotransmitter effect in the cortex.