Schmidt-Kastner R, Wietasch K, Weigel H, Eysel U T
Department of Neurophysiology, Medical Faculty, Ruhr-Universität Bochum, Germany.
Int J Dev Neurosci. 1993 Apr;11(2):157-74. doi: 10.1016/0736-5748(93)90076-p.
Immunohistochemical staining for glial fibrillary acidic protein (GFAP) is standard for visualization of reactive astrocytes in tissue sections, whereas various forms of astrocytic damage remain to be described in detail. In this study we tested differences in GFAP labeling in reactive astrocytes and in glial cells damaged by ischemia and edema. Studies were performed in the anatomically well defined visual system of rat. Basic staining patterns for GFAP were established in subcortical visual nuclei and visual cortex. In the first model, deafferentation of visual centers was performed by unilateral optic nerve lesion, and characteristic changes of GFAP labeling in reactive astrocytes were studied at 0.5, 1, 1.5, 2, 4, 8 and 21 days after lesion. Initial changes were seen in the deafferented superior colliculus at 1 day after deafferentation with a diffuse increase and stellate types of reactive cells formed at 2-8 days. In the second model, small ischemic infarcts were produced in the visual cortex of rats using the method of photochemically-induced thrombosis. GFAP labeling with a polyclonal antiserum was massively enhanced in the infarct at 4 hr. Characteristic morphological changes in damaged astrocytes were seen which were also identified in experiments with simulated global ischemia. In the surround of the infarct, swelling of astrocytes also caused increased labeling. At 3-4 days infarction typical reactive astrocytes surrounded the lesioned area. In conclusion, these immunohistochemical studies on GFAP in rat visual system allow for the following classifications. (a) Normal astrocytes vary in labeling at different anatomical localizations. (b) Reactive astrocytes show enhanced labeling and larger cell-size within an interval of 1-2 days after lesion. (c) Astrocytes damaged by ischemia reveal increased labeling of disintegrating cellular elements within hours after a lesion. (d) Swollen astrocytes undergo enhanced labeling in areas with vasogenic edema.
胶质纤维酸性蛋白（GFAP）免疫组织化学染色是在组织切片中观察反应性星形胶质细胞的标准方法，而各种形式的星形胶质细胞损伤仍有待详细描述。在本研究中，我们测试了反应性星形胶质细胞以及因缺血和水肿而受损的神经胶质细胞中GFAP标记的差异。研究在大鼠解剖结构明确的视觉系统中进行。在皮质下视觉核和视觉皮层中建立了GFAP的基本染色模式。在第一个模型中，通过单侧视神经损伤使视觉中枢去传入，在损伤后0.5、1、1.5、2、4、8和21天研究反应性星形胶质细胞中GFAP标记的特征性变化。去传入后1天，在去传入的上丘中可见初始变化，2 - 8天形成弥漫性增加和星状类型的反应性细胞。在第二个模型中，使用光化学诱导血栓形成的方法在大鼠视觉皮层中产生小的缺血性梗死灶。4小时时梗死灶中用多克隆抗血清进行的GFAP标记大量增强。可见受损星形胶质细胞的特征性形态变化，在模拟全脑缺血的实验中也得到了证实。在梗死灶周围，星形胶质细胞肿胀也导致标记增加。梗死3 - 4天时，典型的反应性星形胶质细胞围绕病变区域。总之，这些对大鼠视觉系统中GFAP的免疫组织化学研究得出以下分类。（a）正常星形胶质细胞在不同解剖位置的标记有所不同。（b）反应性星形胶质细胞在损伤后1 - 2天内显示标记增强且细胞尺寸增大。（c）缺血损伤的星形胶质细胞在损伤后数小时内显示解体细胞成分的标记增加。（d）肿胀的星形胶质细胞在血管源性水肿区域标记增强。
