Movement activity recovers the loss of spines owing to chronic immobilization.

In chronically movement-restricted Wistar rats, we described a significant decrease of spines along apical shafts of layer V cortical pyramids. Current study indicates that the liberation at 40 days of rats whose movements had been restricted since 20 days of age produces a gradual recovery of the number of spines, reaching the control values at 80 days of age and that this process occurred faster in the motor than in the sensory cortices. Nevertheless, when R(20) rats were liberated at 80 days, the number of spines had not fully recovered when rats were 120 days old. Spine recovery is a form of cortical experience-dependent plasticity.