Effects of different delayed exercise regimens on cognitive performance in fimbria‑fornix transected rats

Studies have shown that exercise can positively influence cognitive performance after brain injury. This study investigated the effects of different exercise regimens on allocentric place learning after fimbria‑fornix (FF) transection. One hundred and sixteen pre‑shaped rats were subjected either to a mechanical transection of the FF or control sham surgery and divided into following groups: i) no exercise (NE), ii) voluntary exercise in a running wheel (RW), iii) forced swimming exercise administered as interval training of short (3x5 min) duration (FS‑SI), iv) forced swimming exercise administered as interval training of long (3x15 min) duration (FS‑LI), v) forced swimming exercise administered as one session of short (5 min) duration (FS‑SS), and vi) forced swimming exercise administered as one session of long (15 min) duration (FS‑LS). The exercise was initiated 21 days post‑surgery. Subsequently, all animals were administered 28 acquisition sessions in an 8‑arm radial maze. Both sham operated and lesioned animals showed a significant learning response, however, the lesion induced a marked and lasting impairment, which was not alleviated neither by voluntary nor forced (spaced or one‑session only) exercise regimens. Exercise regimens had no effect on the place learning of control sham animals. We conclude that the lesion location as well as factors related to the exercise‑ and cognitive testing protocols can profoundly influence the potential of exercise as a general recovery‑promoting method.