The effect of exercise on trkA in the contralateral hemisphere of the ischemic rat brain.

Activation of the trkA pathway has been widely accepted as a crucial factor for neuronal survival during cerebral ischemia. Findings from earlier studies have suggested that exercise changed neurotrophic factors and trk family in an ischemic rat model. In this study, we investigated the question of whether or not treadmill exercise improves motor function in an ischemic rat model, and whether or not the result is associated with trkA, responding to NGF. Adult male Sprague-Dawley rats underwent surgery for permanent ischemia, followed by either 12 days of treadmill exercise or non-exercise. We found that exercise increased the level of trkA and NGF proteins in the contralateral hemisphere and improved the motor behavior index. Our data indicate that treadmill exercise ameliorates motor performance via the elevation of trkA and NGF proteins in the contralateral hemisphere after permanent brain ischemia.