CELLULAR-DISTRIBUTION OF PARVALBUMIN IMMUNOREACTIVITY IN THE PERIPHERAL VESTIBULAR SYSTEM OF 3 RODENTS

The cellular distribution of parvalbumin immunoreactivity in the vesti bular peripheral system of mouse, rat, and guinea pig was investigated by light and electron microscopy. Parvalbumin was found in all neuron s of the vestibular ganglia of these species but in the sensory epithe lia immunoreactivity was restricted to type I hair cells localized exc lusively in the central areas. The very intense staining pattern was s imilar in the cristae ampullares and utricles of all three species but a faint immunoreaction was also detectable in sensory cells of periph eral areas of rat cristae. The parvalbumin-immunoreactive type I senso ry cells are connected by nerve fibres of the calyx unit type which ar e known selectively to contain calretinin.