[Study of the vestibular efferent connections of the anterior, lateral, and posterior semicircular canals of guinea pig labyrinth].

Brainstem neurons projecting to the anterior, lateral and posterior semicircular canal ampullae (vestibular efferent neurons) were identified in guinea pigs using retrograde labelling with fluorescent primuline. Two bilateral groups of such neurons located dorsally and ventrally of the facial nerve trajectory were found.