Effects of Swimming Exercise on Learning and Memory in the Kainate-Lesion Model of Temporal Lobe Epilepsy

Abstract

Introduction: An aerobic exercise (Ex) augments neurogenesis and may ameliorate learning and memory deficits in the rat Kainic Acid (KA) model of temporal lobe epilepsy in the shortterm but whether it reverses learning and memory deficits after a substantial period of delay remains unclear. Aim: This study tests the hypothesis that aerobic Ex attenuates the learning and memory deficits associated with kainate seizures in the long-term. Materials and Methods: A total of 60 rats were subjected to chemical lesioning using KA and to an Ex intervention consisting of a 30 days period of daily swimming for 15 min, immediately after KA lesioning (immediate exposure) or after a 60 days period of normal activity (delayed exposure). We evaluated spatial learning on a T-maze test, expressed as percentage of correct responses. We evaluated memory on a passive-avoidance test, expressed as time spent in a compartment in which the rats were previously exposed to an aversive stimulus. Results: Ex increases the percentage of correct responses, percentage bias, and number of alternations, associated with the T-maze testing for the normal control, sham-operated control and kainate-lesioned animals after both immediate and delayed exposures to Ex. Ex decreased the time exposed to the aversive stimulus in the smaller compartment of the twocompartment passive-avoidance test, also for the normal control, sham-operated control and kainate-lesioned animals after both immediate and delayed exposures to Ex. Conclusion: These findings suggest that, after temporal lobe epileptic seizures in rats, swimming exercise may attenuate the learning and memory deficits, even if the exercise treatment is delayed.

Keywords

• aerobic exercise
• hippocampus
• kainic acid
• motor cortex
• neurogenesis
• rats
• seizures