Vestibular Connections of the Brain Stem

Abstract

This investigation is an attempt to study, by electrophysiological technics, the influence of the connecting fibers upon the activity of the 4 pairs of vestibular nuclei and to record the activity which is released in the reticular formation when the receptors in the crista ampullaris are adequately stimulated by movement of the endolymph produced by acceleratory rotation. Earlier histological studies have shown the existence of fibers connecting the primary vestibular nuclei of one side to those of the other. That these few and scattered fibers would mediate some of the activity from one group of nuclei to the other group of nuclei is an assumption which is not borne out by the present investigation involving electrical recording from these nuclei during simultaneous and adequate vestibular stimulation. Anatomical connections between the vestibular nuclei and the reticular formation have also long been known. By recording the impulse activity generated in response to vestibular stimulation from isolated units in the reticular formation, it has been demonstrated exptly. that the formation is connected to both the homolateral and the contralateral vestibular nuclei.