Long-lasting induction of brain-derived neurotrophic factor is restricted to resistant cell populations in an animal model of status epilepticus

We have recently characterized an animal model of status epilepticus induce d by a single intraseptal injection of kainate. Under these conditions, the re is a delayed expanding apoptotic hippocampal and amygdalar cell death. I n order to further characterize this animal model, we have performed a deta iled time-course analysis of the appearance of cell death, brain-derived ne urotrophic factor messenger RNA expression and astroglial and microglial re sponse in different brain areas related to the limbic system. We found a lo ng-lasting delayed apoptotic cell death in the hippocampal formation, amygd ala, medial thalamus, dorsal endopiriform nucleus and multiple cortical are as from two to 21 days post-injection. There was a spatiotemporal correlati on between the appearance of cell death and induction of brain-derived neur otrophic factor messenger RNA expression in the areas studied, and interest ingly this induction was found in non-degenerating cells. We conclude that our animal model of status epilepticus exhibits remarkable features of recurrent seizure activity and provides evidence for a neuropr otective role of brain-derived neurotrophic factor against seizure-induced apoptotic cell death. (C) 2001 IBRO. Published by Elsevier Science Ltd. All rights reserved.