Corticofugal connections between the cerebral cortex and brainstem vestibular nuclei in the macaque monkey

摘要: The distribution of cortical efferent connections to brainstem vestibular nuclei was quantitatively analysed by means retrograde tracer substances injected into different electrophysiologically identified parts the nuclear complex five Java monkeys (Macaca fascicularis). Three polysensory areas were found have a substantial projection nuclei: area 2v located at tip intraparietal sulcus, parietoinsular cortex (PIVC) covering most occipital part granular insula (Ig) and retroinsular (Ri or reipt), dorsolateral somatosensory 3a (“area 3aV” neck/trunk region). From physiological recording experiments, these three fields known contain many neurons responding stimulation semicircular canals as well optokinetic (area 2v, PIVC) stimuli (PIVC, 3a). These regions form inner circuit. Besides fields, other circumscribed macaque brain also project directly postarcuate premotor 6pa), agranular adjacent dysgranular around cingulate sulcus 6c/23c), predominantly visual (optokinetic) association field fundus lateral T3). are with structures Only few for cytoarchitectonic 7. Significant differences between innervation patterns axons originating in six mentioned ending various compartments complex. Vestibular dominant output gaze motor system receive preferably from cortex. their primary skeletomotor centers, however, stronger 6pa 3a. ventrolateral nucleus, which sends both oculomotor systems spinal cord, receives its main efferents somatomotor 6 3aV. Through may influence vestibuloocular vestibulocollic reflexes. It is speculated that corticofugal inhibitory, suppressing reflexes during cortically controlled goal-directed movements. © 1994 Wiley-Liss, Inc.