Electron microscopical evidence of synaptic reorganization in the contralateral motor cortex of adult rats following facial nerve lesion.

Here we report on the rapid changes in the motor cortex of the rat following peripheral lesioning of a motor nerve. Facial nerve transection increases synaptic reorganization (autophagy, lysosomal degradation of synaptic components) already within 4 h after lesion. These changes occur in the motor cortex of both hemispheres, i.e. on the same and contralateral sides. An increase in the number of presynaptic lysosomes was transient and returned to below normal values within 24 h after facial nerve transection.