EN
BACKGROUND AND AIM: Transient focal cerebral ischemia is stimulus triggering reactive astroglial response characterized as the cellular proliferation and restoring of differentiation abilities necessary for reduction of the consequences of primary brain lesion and separation of ischemia. Growing evidence of data point to specific, context-dependent character of this response dependent from the pathological stimuli, intensity of lesion and time-lapse from the beginning of the pathological process. In our study we aimed to assess the potential for proliferation and differentiation of reactive astroglia after transient focal brain ischemia in the rat. METHODS: Transient focal cerebral ischemia was evoked in 20 adult Wistar rats by placement of the surgical thread into the carotid artery and occlusion of the middle cerebral artery for 1 h. The post operative survival period was up to 6 weeks. Immunocytochemical double-stainings for glial fibrillary acidic protein (GFAP), with proliferative (Ki-67 and Pax6,) and characteristic for various stages of gliogenesis (nestin and S100beta protein) markers were performed, with subsequent confocal microscopic study. RESULTS: The apparent differences in the pattern of colocalization within GFAP-immunorecative (ir) astrocytes were observed in the survival period. The intensity of double-labeling for the studied markers increased gradually after 24 h after initiating the ischemia. Intense hypertrophic reaction and increased concentration of GFAPir fibers was observed especially after two weeks of reperfusion. CONCLUSION: The astroglial reaction in the course of reperfusion indicate regaining of the morphological features, characteristic for the earlier developmental stages, as well as the development of proliferative capacities. The considerable potential of astroglial proliferative response even after short-lasting transient cerebral ischemia must be taken into account in the future studies of cerebral infarcts.