EN
The sources of corticovestibular projections from the cerebellar posterior lobe vermis and hemisphere in the rabbit were investigated by the retrograde horseradish peroxidase (HRP) tracing method. Following ionophoretic injections into various subdivisions of the vestibular nuclear complex (VNC), labelled Purkinje neurones were identified ipsolaterally in all vermal lobules (VI through IX) and some regions of the hemisphere.The results indicate that projection is profuse and directed to all four nuclei of VNC.The labelling suggests some topographical relationships between lobules and especially sublobules of the posterior lobe and individual nuclei of VNC.The major projection derives from lobule VIII whereas that from lobule VII is small.Projection from the hamisphere arise mainly from crus I and crus II of the ansiform lobule.Those from the copula pyramids, lobule HV and the ventral paraflocullus are sparse.In the present study a topographical relationships were more precisely established than before because the technique revealed VNC afferents from iondividual sublobules of the cerebellar posterior lobe cortex.