Atypical Innervation Pattern of Human Vestibular Hair Cells

Abstract

Human vestibular sensory cpithclia of macula utriculi were examined in 3 cases with acoustic neurinoma by intermediate voltage electron microscope. The innervation pattern of vestibular hair cells was studied by means of computer aided three-dimensional reconstruction technique. The sensory epithclia were fairly well preserved. Most of type I and all of type II hair cells appeared normal. However, some type I hair cells were incompletely surrounded by nerve calyces and received direct contact from the efferent nerve endings. These type I hair cells were also innervated by a few neighboring afferent nerve calyces. These atypical type I hair cells constituted 5 8% of the total number of hair cells.

Key Words:

• efferent nerve ending
• electron microscope
• nerve calyx
• type I hair cell
• three-dimensional reconstruction