Ajtai B M, Kállai L, Kálmán M
Department of Anatomy, Histology and Embryology, Semmelweis University of Medicine, Budapest, Hungary.
Exp Neurol. 1997 Jul;146(1):151-8. doi: 10.1006/exnr.1997.6496.
In this study, the glial reactions to stab wounds were investigated on a large population of newborn (P0) and fetal rats, by the immunohistochemical staining of the glial fibrillary acidic protein. The lesions penetrated both the cortex and the diencephalon. The fetuses were lesioned in utero from the 17th embryonic day (E17) and were born on E22 or E23 in the natural way. In the cortex usually no reactive gliosis developed although definitive tissue destructions remained after the lesion. Weak and incomplete glial reactions were observed in a few cases of E20 or P0 lesions only. In the diencephalon, however, the same stabbings provoked massive glial reactions. The timing and the morphology of this reaction were similar to those found in adult animals. At E17 the lesion did not result in reactive gliosis even in the diencephalon. Our study highlights two phenomena: (i) depending on the brain area servere glial reactions can already follow fetal lesions, and (ii) the appearance of the capability for glial reactions may be a stage of the local tissue maturation in every brain area and cannot be considered as a function of brain development in general. Probably, the capability for glial reactions can take place only when certain histogenetic processes (e.g., cell migration, axon growth, apoptosis) have been at least mostly accomplished, but which of the local development events are the determining ones remains to be investigated.
在本研究中，通过对胶质纤维酸性蛋白进行免疫组织化学染色，在大量新生（P0）和胎鼠上研究了胶质细胞对刺伤的反应。损伤穿透了皮质和间脑。胎儿在胚胎第17天（E17）时在子宫内受到损伤，并以自然方式在E22或E23出生。在皮质中，通常不会发生反应性胶质增生，尽管损伤后仍存在明确的组织破坏。仅在少数E20或P0损伤的病例中观察到微弱且不完全的胶质反应。然而，在间脑中，相同的刺伤引发了大量的胶质反应。这种反应的时间和形态与成年动物中发现的相似。在E17时，即使在间脑中，损伤也不会导致反应性胶质增生。我们的研究突出了两个现象：（i）取决于脑区，严重的胶质反应可能已经在胎儿损伤后出现；（ii）胶质反应能力的出现可能是每个脑区局部组织成熟的一个阶段，而不能被视为一般脑发育的函数。可能，只有当某些组织发生过程（例如，细胞迁移、轴突生长、细胞凋亡）至少大部分完成时，才会发生胶质反应能力，但哪些局部发育事件是决定性的仍有待研究。
