Chvátal A, Pastor A, Mauch M, Syková E, Kettenmann H
Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague 4.
Eur J Neurosci. 1995 Jan 1;7(1):129-42. doi: 10.1111/j.1460-9568.1995.tb01027.x.
Four types of glial cells could be distinguished in the grey matter of rat spinal cord slices at postnatal days 1-19 (P1-P19), based on their pattern of membrane currents as revealed by the whole cell patch clamp technique, and by their morphological and immunocytochemical features. The recorded cells were labelled with Lucifer Yellow, which allowed the subsequent identification of cells using cell-type-specific markers. Astrocytes were identified by positive staining for glial fibrillary acidic protein (GFAP). These were morphologically characterized by multiple, very fine and short processes and electrophysiologically by symmetrical, non-decaying K+ selective currents. Oligodendrocytes were identified by a typical oligodendrocyte-like morphology, lack of GFAP staining and positive labelling with a combination of O1 and O4 antibodies (markers of the oligodendrocyte lineage), and their membrane was dominated by symmetrical, passive, decaying K+ currents. The third population of glial cells was also characterized by positive staining for O1/O4 or only for O4 antigens, lack of GFAP staining and, in some cells, oligodendrocyte-like morphology. However, these cells could be distinguished by the presence of inwardly rectifying (KIR), delayed outwardly rectifying (KDR) and A-type K+ currents (KA), representing the most likely glial precursor cells of the oligodendrocyte lineage. The fourth population of glial cells had small somata and a widespread network of long processes with no apparent orientation preference. In one case, processes were positively labelled with GFAP, while 30% were characterized by faint, diffuse staining. These cells expressed a complex pattern of voltage-gated channels, namely Na+, KDR, KA and KIR channels. In contrast to neurons, the amplitude of Na+ currents was at least one order of magnitude smaller than the K+ currents, and none of these cells showed the ability to generate action potentials in the current clamp mode. Since none of these cells could be labelled by oligodendrocyte markers we assume that they were either astrocytes or glial precursor cells of the astrocyte lineage. The four cell types were found in all regions of the grey matter. When randomly accessing the glial cells, the probability of recording from the oligodendrocyte precursor cells and the glial cells with Na+ currents decreased during development. At P1-P3, 50% of the cells revealed the Na+ current, while at P13-P15 only 18% did. Concomitantly, the number of glial cells with astrocyte- and oligodendrocyte-like membrane currents increased from 19 and 12% to 41 and 35.5% respectively.(ABSTRACT TRUNCATED AT 400 WORDS)
根据全细胞膜片钳技术所揭示的膜电流模式以及形态学和免疫细胞化学特征，在出生后1 - 19天（P1 - P19）的大鼠脊髓切片灰质中可区分出四种类型的神经胶质细胞。记录的细胞用荧光黄标记，这使得随后能够使用细胞类型特异性标记物来鉴定细胞。星形胶质细胞通过胶质纤维酸性蛋白（GFAP）阳性染色来鉴定。其形态学特征为具有多个非常细小且短的突起，电生理学特征为对称的、不衰减的K⁺选择性电流。少突胶质细胞通过典型的少突胶质细胞样形态、缺乏GFAP染色以及用O1和O4抗体组合（少突胶质细胞谱系标记物）阳性标记来鉴定，其膜以对称的、被动的、衰减的K⁺电流为主。第三类神经胶质细胞也以O1/O4或仅O4抗原阳性染色、缺乏GFAP染色为特征，并且在一些细胞中具有少突胶质细胞样形态。然而，这些细胞可通过内向整流（KIR）、延迟外向整流（KDR）和A 型K⁺电流（KA）的存在来区分，它们最有可能是少突胶质细胞谱系的神经胶质前体细胞。第四类神经胶质细胞具有小的胞体和广泛的长突起网络，且无明显的方向偏好。在一个案例中，突起被GFAP阳性标记，而30%的细胞具有微弱的、弥漫性染色特征。这些细胞表达了复杂的电压门控通道模式，即Na⁺、KDR、KA和KIR通道。与神经元不同，Na⁺电流的幅度比K⁺电流至少小一个数量级，并且这些细胞在电流钳模式下均未显示出产生动作电位的能力。由于这些细胞均不能被少突胶质细胞标记物标记，我们推测它们要么是星形胶质细胞，要么是星形胶质细胞谱系的神经胶质前体细胞。这四种细胞类型在灰质的所有区域均有发现。当随机记录神经胶质细胞时，在发育过程中记录到少突胶质前体细胞和具有Na⁺电流的神经胶质细胞的概率降低。在P1 - P3时，50%的细胞显示有Na⁺电流，而在P13 - P15时只有18%的细胞有。与此同时，具有星形胶质细胞样和少突胶质细胞样膜电流的神经胶质细胞数量分别从19%和12%增加到41%和35.5%。（摘要截断于400字）
