Abstracts

Development of spontaneous seizure following prolonged status-epilepticus (SE) is age dependent and a number of molecular and morphological changes occur following SE have been suggested to contribute to development of spontaneous seizures. Astrogliosis is one such prominent feature of epileptic brain and may play an important role in epileptogenesis. In the present study, we assessed the effect of prolonged SE induced at different ages on GFAP mRNA expression in dentate gyrus (DG)., SE was induced in P10, P20 and adult rats using either lithium/pilocarpine (Li/Pilo) or kainic acid (KA). One, seven and 21 days after SE induction, rats were sacrificed and GFAP mRNA expression was examined in acutely dissected DG using antisense RNA amplification (aRNA) technique., GFAP mRNA expression in DG was increased 3 fold in the adult rats 7 days after Li/Pilo-induced SE and remained high at 21 days. In P20 rats, GFAP mRNA expression was increased 2 fold 1 day after SE and 3 fold 7 days after Li/Pilo or KA induced SE. In contrast, in P10 rats, GFAP mRNA expression did not change at any time point (1 and 7 days) studied following KA induced SE., This study shows that GFAP mRNA expression in DG after SE is age dependent but not model specific. Further, as increase in GFAP occurs prior to and in association with development of epilepsy after SE, these findings support the hypothesis that astrogliosis may be related to epileptogenesis., (Supported by NIH NS38595 to ABK.)