Presence of synapsin I in afferent and efferent nerve endings of vestibular sensory epithelia.

ABSTRACT

The presence and localization of synapsin I were investigated in the cat vestibular epithelium, using a rabbit anti-synapsin I antibody. The staining was performed by immunofluorescence or by a peroxidase-anti-peroxidase technique. A strong immunoreactivity was observed with both methods. It appeared as spherical patches distributed in the lower part of the epithelium. This distribution pattern is very similar to that of the efferent synaptic endings which are filled with microvesicles. Elongated immunoreactive segments were also observed around some hair cells. They suggest the presence of synapsin I in the afferent sensory endings contacting the hair cells. This immunoreactivity occurs in early postnatal and adult stages.