Metabolic brain activity underlying behavioral performance and spatial strategy choice in sedentary and exercised Wistar rats

We have studied the performance of a spatial reference memory task, the navigation strategy and the changes in the cytochrome c oxidase activity (COx) in different brain regions in exercised (forced exercise, 10 consecutive days, 15 min/day) and non-exercised adult Wistar rats. The spatial learning task was carried out in the radial-arm water maze (RAWM) for four days with six daily trials, and on the fifth day, a probe session was run, in which we rotated the position of the distal cues 90° in a clockwise direction. During the four days of training, the exercised group showed shorter latency and distance traveled to find the platform, as well as fewer memory errors and reduced use of non-appropriate navigation strategies according to the protocol of the task (egocentric). Interestingly, the rotation of the cues did not affect the performance of the exercised group, in contrast to the non-exercised group, which spent more time in the center of the maze and traveled longer distance to find the platform. Finally, higher COx activity in the cingulate and the retrosplenial cortices, as well as in the dorsal CA1 and CA3 was found in the exercised group. All in all, it seems that the exercise favored the configuration of an efficient and accurate cognitive map of the environment, which was supported by our finding that the rotation of the cues, without altering their overall configuration, did not affect performance. The brain regions with higher COx activity in the exercised group seem to be involved in this function.