Ultrastructural analysis of rat brain tissue following systemic kainate administration.

Abstract

Morphological studies in models of experimental epilepsy have mainly focused on pathohistological changes of nerve cells (Schwob et al., 1980; Ben-Ari et al., 1981). Although it is evident, that neurons are the primary target in the action of excitotoxins, recent evidence suggests that besides direct neurotoxicity other pathogenetic mechanisms play an important role in the development of postepileptic brain damage. It is thus interesting to note, that irreversible neuropathological changes following kainic acid (KA) induced seizures not only involve nerve cells, but also glia, myelin sheaths and blood vessels (Sperk et al., 1983). In our present study we describe the sequence of morphological events in the limbic system of rats, systemically injected with KA. Our findings indicate that cytotoxic brain edema and subsequent focal ischemia plays a central role in the pathogenesis of irreversible seizure induced brain lesions.