Structural changes in astrocytes induced by seizures in a mode of temporal lobe epilepsy.

Injection of iron-chloride solution unilaterally into the hippocampus of albino rats induced transient seizure activity which lasted approximately 2 weeks. Frontal and parietal cortices of experimental rats, control rats which received NaCl injections, and unoperated normal rats were compared by means of a Golgi stain which demonstrated astrocytes and their processes in their entirety. Morphometric analysis showed that cortical astrocytes of rats having intermittent seizure activity over a prolonged period were significantly larger than cortical astrocytes of control rats. These findings indicate that seizure activity causes structural brain changes at anatomical sites distant from the hippocampal seizure focus. Similar phenomena may contribute to the development of psychiatric and neurological changes in the epileptic patient.