Vestibular nuclear efferents to the nucleus raphe pontis, the nucleus reticularis tegmenti pontis and the nuclei pontis in the cat

The projection of the vestibular nuclei to the pontine tegmentum was investigated by means of anterograde transport of tritiated leucine. Dense patches of terminal labeling were observed in the contralateral nucleus raphe pontis and the nucleus reticularis tegmenti pontis in cases where the injection involved the medial and descending vestibular nuclei. Following injections in the superior vestibular nucleus and group Y, weaker termination, also patchlike, was observed in the same tegmental nuclei, and in addition in the dorsomedial pontine nuclei proper. The results are discussed in relation to the position of the nucleus raphe pontis and the nucleus reticularis tegmenti pontis in the oculomotor pathways.