DISTRIBUTION OF GABAERGIC NEURONS AND AXON TERMINALS IN THE MACAQUE STRIATE CORTEX
DISTRIBUTION OF GABAERGIC NEURONS AND AXON TERMINALS IN THE MACAQUE STRIATE CORTEX
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DOI：
10.1002/cne.902640107
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发表时间：
1987-10-01
影响因子：
2.5
通讯作者：
TOWLES, AC
中科院分区：
文献类型：
--
作者：
FITZPATRICK, D;LUND, JS;TOWLES, AC
谷氨酸脱羧酶（GAD）抗血清。-氨基丁酸（GABA）已被用来表征猕猴纹状皮层中假定的GABA能神经元和轴突终端的形态和分布。尽管这些抗血清在检测细胞体和终末的相对灵敏度上存在一些差异，但总体标记模式似乎非常相似。gaba能轴突末端在已知接收外侧膝状核大部分投射的区域尤为突出；4C、4A层和3层富含细胞色素的斑块。在4A层，gaba能末端呈蜂窝状分布，似乎与该区域的曲状末端的空间格局密切匹配。在4c . β层中含有扁平囊泡并形成对称突触接触（FS终端）的轴突末端的定量分析。和第5层的研究表明，GAD和GABA轴突末端标记在曲状受体区域的突出，至少在一定程度上是由于这些区域存在较大的GABA能轴突末端。gaba能细胞体及其初始树突节段表现出非锥体神经元的形态特征，存在于纹状皮层各层。2-3A、4A和4c层中GAD和GABA免疫反应神经元的密度最大。gaba能神经元在3层内的分布与细胞色素氧化酶在该区域的斑片状分布似乎不相关；即，在第3层细胞色素丰富区和细胞色素贫乏区，GAD和GABA免疫反应神经元的密度无显著差异。标记和未标记神经元的计数表明，GABA免疫反应神经元至少占纹状皮层神经元的15%。第1层与其他皮层层不同，其gaba能神经元的比例高（77-81%）。在其他层中，gaba能神经元的比例从2-3A层的约20%到5和6层的12%不等。最后，GAD和GABA免疫反应神经元的大小和树突排列存在明显的层状差异。板4 c.beta。和6层与其他层的区别在于存在大量的gaba能神经元，其中一些具有水平扩散的树突。浅层内的gaba能神经元明显较小，并且大多数具有垂直定向的树突。这些结果支持了gaba能神经元在猕猴纹状皮层神经元中占很大比例的观点，并且gaba能神经元的数量和类型存在层间差异，这种差异可能与理解gaba介导的抑制对纹状皮层功能的贡献有关。
Antisera to glutamic acid decarboxylase (GAD) and .gamma.-aminobutyric acid (GABA) have been used to characterize the morphology and distribution of presumed GABAergic neurons and axon terminals within the macaque striate cortex. Despite some differences in the relative sensitivity of these antisera for detecting cell bodies and terminals, the overall patterns of labeling appear quite similar. GABAergic axon terminals are particularly prominent in zones known to receive the bulk of the projections from the lateral geniculate nucleus; laminae 4C, 4A, and the cytochrome-rich patches of lamina 3. In lamina 4A, GABAergic terminals are distributed in a honeycomb pattern which appears to match closely the spatial pattern of geniculate terminations in this region. Quantitative analysis of axon terminals that contain flat vesicles and form symmetric synaptic contacts (FS terminals) in lamina 4C.beta. and in lamina 5 suggest that the prominence of GAD and GABA axon terminal labeling in the geniculate recipient zones is due, at least in part, to the presence of larger GABAergic axon terminals in these regions. GABAergic cell bodies and their initial dendritic segments display morphological features characteristic of nonpyramidal neurons and are found in all layers of striate cortex. The density of GAD and GABA immunoreactive neurons is greatest in laminae 2-3A, 4A, and 4C.beta.. The distribution of GABAergic neurons within lamina 3 does not appear to be correlated with the patchy distribution of cytochrome oxidase in this region; i.e., there is no significant difference in the density of GAD and GABA immunoreactive neurons in cytochrome-rich and cytochrome-poor regions of lamina 3. Counts of labeled and unlabeled neurons indicate that GABA immunoreactive neurons make up at least 15% of the neurons in striate cortex. Layer 1 is distinct from the other cortical layers by virtue of its high percentage (77-81%) of GABAergic neurons. Among the other layers, the proportion of GABAergic neurons varies from roughly 20% in laminae 2-3A to 12% in laminae 5 and 6. Finally, there are conspicuous laminar differences in the size and dendritic arrangement of GAD and GABA immunoreactive neurons. Lamina 4C.beta. and lamina 6 are distinguished from the other layers by the presence of populations of large GABAergic neurons, some of which have horizontally spreading dendritic processes. GABAergic neurons within the superficial layers are significantly smaller and the majority appear to have vertically oriented dendritic processes. These results provide support for the idea that GABAergic neurons make up a significant proportion of the neurons within the macaque striate cortex and that there are laminar differences in the number and the types of GABAergic neurons.sbd.differences that may be relevant for understanding the contributions of GABA-mediated inhibition to striate cortex function.