Quantitative analysis of neurons and glial cells in the rat somatosensory cortex, with special reference to GABAergic neurons and parvalbumin-containing neurons
Quantitative analysis of neurons and glial cells in the rat somatosensory cortex, with special reference to GABAergic neurons and parvalbumin-containing neurons
复制标题
大鼠体感皮层神经元和神经胶质细胞的定量分析，特别是 GABA 能神经元和含小清蛋白的神经元
作者：
J. Ren;Y. Aika;C. Heizmann;T. Kosaka
用体视学方法，即解剖器，用甲苯胺蓝染色，塑料包埋的0.5 μ m厚切片对大鼠躯体感觉皮层（桶区）的神经元和神经胶质细胞的数量进行了估计，切片之间相距1.5 μm。在相邻的半薄切片上，通过接种后免疫细胞化学方法进一步分析这些圆盘计数的细胞的化学性质。因此，我们能够定量分析五种细胞类型的数量，分布和比例：（1）γ-氨基丁酸（GABA）阴性神经元，（2）GABA样免疫反应阳性神经元，（3）GABA样免疫反应阳性神经元，（4）GABA样免疫反应阳性神经元，（5）GABA样免疫反应阳性神经元，（6）GABA样免疫反应阳性神经元，（7）GABA样免疫反应阳性神经元，（8）GABA样免疫反应阳性神经元，（9）GABA样免疫反应阳性神经元，（10）GABA样免疫反应阳性神经元GABA-LIR神经元;（3）特异性钙结合蛋白小白蛋白免疫反应（PV-IR）神经元，GABA-LIR神经元的一个亚群;（4）S-100β-LIR胶质细胞（星形胶质细胞）;和（5）S-100β-阴性神经胶质细胞（少突胶质细胞和小胶质细胞）。大鼠躯体感觉皮层的总细胞密度、胶质细胞密度和神经元密度分别为85.4 × 103/mm 3、30.5 × 103/mm 3和54.9 × 103/mm 3。在所有神经元中，分别有25%和14%为GABA-LIR和PV-IR;所有PV-IR神经元均为GABA-LIR，因此约54%的GABA-LIR神经元为PV阳性。单位表面积1 mm ~ 2下的体感皮层总细胞数为171.6 × 103，神经元和胶质细胞数分别为110.2 × 103和61.4 × 103。GABA-LIR阳性神经元27.7 × 103个，PV阳性神经元15.0 × 103个，GABA-LIR阴性神经元12.7 × 103个。各组细胞的层状分布有显著差异，表明细胞的组成在各层间不同。GABA-LIR神经元密度在第IV层最高。PV-IR神经元的数密度在IV层中比在II/III、V和VI层中高2-4倍，而PV-阴性GABA-LIR神经元的数密度在整个层中几乎是恒定的。
SummaryThe number of neuronal and glial cells in the rat somatosensory cortex (barrel area) has been estimated by a stereological method, the disector, using pairs of toluidine blue-stained, plastic-embedded 0.5-μm-thick sections, 1.5 μm distant from each other. Chemical properties of those disector-counted cells were further analyzed by postembedding immunocytochemical methods on adjacent semithin sections. Thus we were able to analyze quantitatively number, distribution, and proportion of five cell types: (1) gamma-aminobutyric acid-(GABA)-negative neurons; (2) GABA-like immunoreactive (GABA-LIR) neurons; (3) a specific calcium-binding protein parvalbumin-immunoreactive (PV-IR) neurons, a subpopulation of GABA-LIR neurons; (4) S-100β-LIR glial cells (astrocytes); and (5) S-100β-negative glial cells (oligodendrocytes and microglia). The densities of total cells, glial cells, and neurons in the rat somatosensory cortex were 85.4 × 103/mm3, 30.5 × 103/mm3, and 54.9 × 103/mm3, respectively. Of all neurons 25% and 14% were GABA-LIR and PV-IR, respectively; all PV-IR neurons are GABA-LIR, and thus about 54% of GABA-LIR neurons are PV-positive. The number of total cells under a unit surface area of 1 mm2 through the thickness of the somatosensory cortex was 171.6 × 103; the number of neurons and glial cells were 110.2 × 103 and 61.4 × 103, respectively. There were 27.7 × 103 GABA-LIR neurons and 15.0 × 103 and 12.7 × 103 PV-IR neurons and PV-negative GABA-LIR neurons, respectively. The laminar distribution of each group of cells shows prominent differences, indicating that the cellular composition was different from layer to layer. The density of GABA-LIR neurons was highest in layer IV. The numerical density of PV-IR neurons was 2–4 times higher in layer IV than in layers II/III, V, and VI, whereas that of PV-negative GABA-LIR neurons was almost constant throughout the layers.