Morphology Of The Vestibular Nerve: III. Analysis Of The Calibers Of The Myelinated Vestibular Nerve Fibers In Man At Various Ages

Abstract

An analysis of the calibers of the preganglionic portion of the myelinated vestibular nerve fibers in man at various ages has been made. In all 10 210 fibers were analysed. The material consisted of nerve specimens from one newborn, 4 adults with “normal” or near-“normal” numbers of vestibular fibers and 4 old persons with distinct reductions in number of nerve fibers. In the newborn the fibers were generally thinner than in the adult and old persons. The ampullary nerves and especially the two superior branches, contained proportionally more thick fibers than the macular nerves. In the old age group the proportion of thick fibers was less than in the adult group, this was particularly evident in the ampullary nerve branches. It could not be determined whether this was caused by disappearance of the thick fibers or was the result of a general involution of all nerve fibers in old age.