Kálmán M, Ajtai B M, Sommernes J H
Dept. of Anatomy, Histology and Embryology, Semmelweis University of Medicine, Tûzoltó 58, Budapest, Hungary, H-1450.
Neural Plast. 2000;7(3):147-65. doi: 10.1155/NP.2000.147.
In this study we investigate the capability of lesions, performed between embryonic day E18 and postnatal day P6, to provoke glial reaction. Two different lesion types were applied: 'severe' lesion (tissue defect) and 'light' lesion (stab wound). The glial reaction was detected with immunostaining against glial fibrillary acidic protein. When performed as early as P0, severe lesions could result in reactive gliosis, which persisted even after a month. The glial reaction was detected at P6/P7 and became strong by P8, regardless of the age when the animals were lesioned between P0 and P5. Namely, a strict limit could be estimated for the age when reactive glia were already found rather than for the age when glial reaction-provoking lesions could occur. After prenatal lesions, no glial reaction developed, but the usual glia limitans covered the deformed brain surface. Light lesions provoked glial reactions when performed at P6. In conclusion, three scenarios were found, depending on the age of the animal at injury: (i) healing without glial reaction, regardless of the remaining deformation; (ii) depending on the size of the lesion, either healing without residuum or with remaining tissue defect plus reactive gliosis; and (iii) healing always with reactive gliosis. The age limits between them were at P0 and P5. The glial reactivity seemingly appears after the end of the neuronal migration and just precedes the massive transformation of the radial glia into astrocytes. Estimating the position of the appearance of glial reactivity among the events of cortical maturation can help to adapt the experimental results to humans.
在本研究中，我们调查了在胚胎第18天（E18）至出生后第6天（P6）之间造成的损伤引发胶质反应的能力。应用了两种不同类型的损伤：“严重”损伤（组织缺损）和“轻度”损伤（刺伤）。通过针对胶质纤维酸性蛋白的免疫染色检测胶质反应。早在P0时进行的严重损伤可导致反应性胶质增生，即使在一个月后仍持续存在。无论动物在P0至P5之间何时受到损伤，在P6/P7时均可检测到胶质反应，并在P8时变强。也就是说，可以估计出发现反应性胶质细胞的年龄有一个严格的界限，而不是引发胶质反应的损伤可能发生的年龄。产前损伤后，未出现胶质反应，但通常的胶质界膜覆盖了变形的脑表面。在P6时进行轻度损伤会引发胶质反应。总之，根据动物受伤时的年龄，发现了三种情况：（i）无论剩余的变形如何，均无胶质反应的愈合；（ii）根据损伤的大小，要么无残留愈合，要么有残留组织缺损并伴有反应性胶质增生；（iii）总是伴有反应性胶质增生的愈合。它们之间的年龄界限在P0和P5。胶质反应性似乎在神经元迁移结束后出现，且恰好在放射状胶质细胞大量转化为星形胶质细胞之前出现。估计胶质反应性在皮质成熟事件中的出现位置有助于使实验结果适用于人类。
