Repeated focal electrical stimulation of the brain is known to produce epileptogenesis, and this phenomenon is recognized as kindling. It is also considered to be a model of temporal lobe epilepsy. In the present study, morphological changes in areas around third ventricle in rat brain were examined according to the progression of kindling stage. Very few Glial Fibrillary Acidic Protein (GFAP)-positive astrocytes were present in ependymal cell layer at CO stage. However, there was a specific increase in GEAP-positive cells in ependymal cell layer at stage C3 as compared to stage CO. Furthermore, GFAP-positive cells showed migration to subependymal zone (SEZ). By stage C5, almost all GEAP-positive cells had migrated to SEZ. While the precise mechanism of this cell migration is not clear, the results suggest a relationship between progression of kindling stage and astrogliosis. (C) 2003 Elsevier B.V. All rights reserved.