The effects of knife cuts of hippocampal pathways on epileptic activity in the seizure-sensitive gerbil.

Previous studies have shown morphological differences in the hippocampal formation of seizure-sensitive gerbils as compared to seizure-resistant gerbils. To determine the significance of these differences, lesions were made of hippocampal afferents and efferents. Seizure-sensitive gerbils with bilateral knife cuts of the perforant path, including those with bilateral fornix lesions, showed no seizure activity following surgery. However, bilateral transections of the fimbria of the fornix, unilateral lesions of the perforant path and sham surgeries had no significant effect on seizure activity. The termination of seizure activity with bilateral lesions of the perforant path suggests that this pathway, as opposed to the fornix, is required for motor seizures in this strain of gerbils.