Projection of Afferents from Individual Vestibular Sense Organs to the Vestibular Nuclei in the Pigeon

Abstract

Schwarz DWF, Schwarz IE. Projection of afTerents from individual vestibular sense organs to the vestibular nuclei of the pigeon. Acta Otolaryngol (Stockh) 1986; 102: 463473.

The projection of individual labyrinthine sensory organs to the brain stem was studied by autoradiography, employing discrete [³H]leucine injections into the sensory epithelia. Within the vestibular nuclei, separate partly overlapping termination areas for each end organ were found in the superior and descending vestibular nuclei, whereas projection temtories in the medial, ventrolateral and tangential nuclei overlapped extensively. A few lagenar fibres terminated in the external cuneate nucleus. Semicircular canals and utricular macula also project to the lateral cerebellar nucleus and the reticular formation. For each semicircular canal a projection system could be traced to distinct subgroups of the extraocular motoneuron pools.

Key Words:

• semicircular canal
• otolitkic macula
• afferents
• vestibular nuclei