Effects of temporal lobe seizures on visual recognition memory in a non-human primate model

Abstract

Patients with temporal lobe epilepsy frequently report memory impairment, which significantly impacts their quality of life. Several studies have demonstrated an association between temporal lobe epilepsy and memory dysfunction, though the underlying mechanisms remain unclear. This study investigates whether a penicillin-induced temporal lobe seizure model in non-human primates (NHPs) replicates the recognition deficits observed in epileptic patients. We recorded hippocampal activity in three NHPs during a visual paired comparison (VPC) task before and during seizures. The penicillin model induced multiple spontaneous, self-terminating temporal lobe seizures over 4–6 h. Seizures were induced after VPC training, and tasks were performed using an eye-tracking system while the animals were seated with head restraint. During the familiarization phase, novel objects were presented and later paired with a new object after a randomized delay (10 or 60 s). While task success rates did not differ between baseline and seizure conditions, we observed prolonged encoding durations. Further studies are needed to elucidate these findings, but this NHP model of temporal lobe epilepsy may provide critical insights into the relationship between epileptic activity and cognitive impairment.