Quinine causes isolated outer hair cells to change length.

The outer hair cells have been shown to exhibit motile properties which are likely to participate in the cochlear performance. Quinine is known to induce hearing loss as well as contraction of skeletal muscle. Isolated outer hair cells were exposed to quinine and tetracaine. This resulted in a biphasic elongation-shortening response, quantitatively as well as qualitatively altered by tetracaine. These findings are in good agreement with similar studies on muscle.