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

Abstract

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 amechanical transection of the FF or control sham surgery and divided into following groups: i) no exercise (NE), ii) voluntary exercise in arunning wheel (RW), iii) forced swimming exercise administered as interval training of short (3x5min) duration (FS‑SI), iv) forced swimming exercise administered as interval training of long (3x15min) duration (FS‑LI), v) forced swimming exercise administered as one session of short (5min) duration (FS‑SS), and vi) forced swimming exercise administered as one session of long (15min) duration (FS‑LS). The exercise was initiated 21days post‑surgery. Subsequently, all animals were administered 28 acquisitionsessions in an 8‑arm radial maze. Both sham operated and lesioned animals showed asignificant learning response, however, the lesion induced amarked 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 ageneral recovery‑promoting method.