Chudler E H, Pretel S, Kenshalo D R
Neurobiology and Anesthesiology Branch, National Institute of Dental Research, Bethesda, MD 20892.
Brain Res. 1988 Jul 19;456(1):57-63. doi: 10.1016/0006-8993(88)90346-0.
The distribution of neurons immunoreactive for glutamic acid decarboxylase (GAD), the synthesizing enzyme of gamma-aminobutyric acid (GABA), was examined in the first (SI) and second (SII) somatosensory cortex of monkeys. GAD-like immunoreactive (GAD-LI) somata and puncta were present in all layers of SI and SII. All GAD-LI somata were identified as non-pyramidal neurons and were most numerous in layer IV of SI and in layer III of SII. Layer IV of SI also contained the highest density of GAD-LI puncta. In SII, GAD-LI puncta were distributed more homogeneously and did not show a dense band of labelled puncta in layer IV. The major and minor diameters of GAD-LI somata in SII ranged from 6.9 to 26.2 micron and from 6.2 to 19.0 micron, respectively. The major diameters of GAD-LI somata in SII were significantly smaller than those in SI in layers I, III and IV. Differences between the distributions of GAD-LI puncta and somata in SI and SII may be accounted for by differences in the number and/or distribution of different types of GABAergic neurons. Functional differences of neurons in SI and SII may be related to the differences in GABAergic inhibitory mechanisms and reflected in the distribution of GABAergic neurons.
在猴子的第一躯体感觉皮层（SI）和第二躯体感觉皮层（SII）中，研究了对谷氨酸脱羧酶（GAD，γ-氨基丁酸（GABA）的合成酶）呈免疫反应的神经元的分布情况。SI和SII的所有层中均存在GAD样免疫反应性（GAD-LI）胞体和斑点。所有GAD-LI胞体均被鉴定为非锥体神经元，在SI的第IV层和SII的第III层中数量最多。SI的第IV层中GAD-LI斑点的密度也最高。在SII中，GAD-LI斑点分布更均匀，在第IV层中未显示出密集的标记斑点带。SII中GAD-LI胞体的长径和短径分别为6.9至26.2微米和6.2至19.0微米。在I、III和IV层中，SII中GAD-LI胞体的长径明显小于SI中的长径。SI和SII中GAD-LI斑点和胞体分布的差异可能是由不同类型GABA能神经元的数量和/或分布差异造成的。SI和SII中神经元的功能差异可能与GABA能抑制机制的差异有关，并反映在GABA能神经元的分布上。
