Abstract
Over the past few decades, the average age at time of spinal cord injury (SCI) has increased. Here we examined locomotor recovery and myelin pathology in both young and aged adult rats following contusion SCI. Our assessment indicates that the rate of locomotor recovery following SCI is significantly delayed in aged rats as compared to young rats, and is associated with a greater degree of pathology and demyelination. Additionally, we examined the effect of voluntary exercise, pre- and post-injury, on locomotor recovery and myelin pathology following contusion SCI. Our data indicate that exercise improves the locomotor recovery of injured aged rats such that it is comparable to the recovery rate of injured young rats, and is associated with a decreased area of pathology and amount of demyelination. Interestingly, the rate of locomotor recovery and myelin pathology in the aged exercised rats was similar to that of the young sedentary rats after injury, indicating that exercise attenuates the delayed recovery of function and associated histopathology in aged rats. These data indicate that there is an age-related delay in locomotor recovery following SCI, and an age-related increase in histopathology following SCI. Importantly, our data indicate that exercise attenuates these age-related deficits following SCI.