Electron microscopic demonstration of cerebello-oculomotor fibres in cat.

Few synaptic buttons with the typical changes of "electron-dense degeneration" were found in the nucleus of the oculomotor nerve of cats, which underwent complete bilateral ablation of the cerebellum. The degenerating buttons were mainly found in the neuropil, contacting small dendritic profiles. For the scanty number of degenerating buttons observed and for the particular location of its terminal buttons, the direct cerebello-oculomotor connection appears to be an ancillary route in the cerebello-oculomotor linkage, which involves mainly polysynaptic routes.