Effects of swimming exercise during pre-adolescence on learning and memory in adult rats: behavioral and electrophysiological approaches

The positive impact of physical activity on age-related memory impairment is well documented. There is no clear report on the effects of pre-adolescent exercise on cognitive abilities in adulthood.

Male Wistar rats (4-week-old) were randomized to a non-swimmer (control, n=20) and swimmer (n=20). The swimmer group trained for 30min a day, 6 days per week, 6 weeks. After the last day, behavior (through passive avoidance learning and radial maze) and electrophysiological techniques were evaluated in rats.

Swimming exercise led to a decrease in the number of trials in the passive avoidance test. In addition, swimming reduced the number of working memory and reference memory errors in the radial maze task. On the radial maze task, the two groups showed equal learning ability in finding the baited food arms by day 15. The results of the recall tests showed that the number of total memory errors and working memory errors was significantly lower in the swimmer group than in the non-swimmer group. Exercise also improved both Population spike (PS) amplitude and field-excited postsynaptic potential slope.

These results revealed that swimming exercise could improve memory by increasing synaptic plasticity in rats.