Motile responses of isolated vestibular hair cells

Vestibular sensory cells were isolated from the utricular macula or crista ampullaris of the guinea pig by enzymatic and mechanical dissociation. Isolated vestibular hair cells, especially type I hair cells, showed an active motile capacity. After exposure to a medium containing high concentration of potassium, or to a hypoosmotic medium, the type I hair cells showed tilting of their hair bundle to about 15 degrees. Given the tight and dense structure of the vestibular epithelium, the changes in shape of the isolated vestibular hair cells may in vivo lead to an influence of the mechano-sensitive stereocilia and modulate stiffness and compliance of the receptor structure as a whole including its cupular or macular relationship. This active mechanical events could be closely related to an active adaptation process.