Figure 4.

Forced locomotion enhances NDF staining in the motor cortex. (A) Rats were sacrificed 3.5 hr or 6.5 hr after walking for 1 hr on a revolving wheel, and the corresponding areas of the motor cortex (marked by arrows) were analyzed by immunostaining with an affinity-purified antibody to NDF. (B) Quantification of the effect of locomotion on NDF expression was performed by counting the number of NDF-positive cells in the indicated layers of the motor cortex. A large increase in cell staining is seen already at 3.5 hr in layers 2–3 of the neocortex, whereas in the deeper layers, including the large pyramidal cells of layers 5 and 6, immunoreactivity increased more slowly. Asterisks indicate an increase above control at a significance level of P < 0.05.