Influence of the extraocular muscle proprioceptors on the orientation of the vestibule-ocular reflex

In the intact brain lamb, unilateral electrolytic lesion of the medial dorso-lateral portion of the semilunar ganglion containing the first order neurons of the eye muscle proprioception induced modifications of the horizontal and vertical vestibule-ocular reflex (HVOR and VVOR) which consisted in marked alterations of the trajectories of the quick phases, while the slow phases were scarcely affected. Similar results were observed after section of the branches described by Winckler in the retrobulbar region along which the extraocular muscle proprioceptive information travels. These findings extend those of previous investigations carried out in decorticate animals.