Abstract

Afferent cup-like terminal; calyx is innervated to type I hair cell, and efferent bouton is connected to calyx. Type II hair cell is directly connected to both afferent and efferent boutons. Vestibular hair cell can influence each other via complex connections of nervous system. Vesibular hair cells are also classified to three morphological classes of vestibular afferents: calyx, dimorphic, and bouton. Calyx type has large cuplike afferent terminals, dimorphic type has additional afferent connection with type II hair cells, and bouton type is a classic type II hair cell which both afferent and efferent terminals are contacted to base of cells. Calyx fibers of type I hair cells have highly irregular spontaneous discharges and the most phasic (adapting) response properties. Otherwise, neural discharge properties of type II hair cells are the most regular and least phasic (tonic). Vestibular system provides sensory information using a complex hair cell system, which has cell-specific ion channels.