TIME-COURSE FOR KINDLING-INDUCED CHANGES IN THE HILAR AREA OF THE DENTATE GYRUS - REACTIVE GLIOSIS AS A POTENTIAL MECHANISM

Recurrent seizure activity induced during kindling has been reported t o cause an increase in the hilar area of the dentate gyrus of the hipp ocampus. To date, very little is known about the mechanism of this inc rease. This study investigated the time course for kindling-induced ch anges in the hilar area of the dentate gyrus at seven days, one month, and two months post-kindling. Hilar area of the dentate gyrus was sig nificantly increased by approximately 46% at seven days and remained e levated at one month, but declined back to control levels by two month s. Glial fibrillary acidic protein (GFAP) immunostaining was also eval uated at the same time points to determine whether kindling-induced ch anges in the hilar area of the dentate gyrus are related to kindling-i nduced glial cell changes. Increases in hilar GFAP immunostaining by a pproximately 57% were observed at seven days and at one month post-kin dling, but not at two months post-kindling. These findings indicate th at kindling-induced changes in the hilar area of the dentate gyrus and kindling-induced glial cell changes follow a similar time course, and that kindling-induced glial cell changes may mediate the observed cha nges in the hilar area of the dentate gyrus. (C) 1998 Elsevier Science B.V. All rights reserved.