Early cerebellar hemispherectomy in the rat. Effects on the maturation of two hindlimb muscles and on lumbar motoneurones

Cerebellar hemispherectomy before the 10th day in rats leads to extensive neuronal remodelling. In the present study the problem was studied whether such early lesions also have effects on the maturation of the soleus and the extensor digitorum longus muscles in the hindleg as well as on the formation of dendrite bundles from motoneurons innervating the soleus muscle. Results indicate consistent left-to-right differences in the numbers of muscle fibres but no differences in muscle differentiation. Dendritic bundles of soleus motoneurons, at the side ipsilateral to the cerebellar lesion are absent or less conspicuous in comparison to the contralateral side or to those bundles in normal rats. Cerebellar lesioning at the 30th day does not affect dendritic bundles.