Efferent Innervation of Vestibular Receptors in the Cat: A Radioautographic Visualization

Abstract

A tritiated amino acid tracing method was used to test the hypothesis that a unilateral group of vestibular efferent neurons of the brain stem may present different innervation patterns to the sensory vestibular epithelia of the ipsi- and contralateral labyrinths. Densitometric analysis of labeled efferent endings suggested a heterogeneity of the efferent projections issuing from a unilateral group of efferent vestibular neurons. Ipsilateral projections predominated in the maculae utriculi and cristae ampullares of the semicircular canals. These findings are discussed as a function of other data related to efferent vestibular control.