Structural similarities between kinocilium of vestibular hair cell and tracheal motile cilium in the guinea pig.

A rapid-freeze, deep-etch method was used to visualize the membrane characteristics as well as the three-dimensional ultrastructural features of a kinocilium of the guinea pig vestibular hair cell. A kinocilium of the vestibular hair cell had a typical ciliary necklace, consisting of six to seven parallel intramembrane particle arrays. The basal body of a kinocilium had a plate-structure called a terminal plate, in its interior. In the shaft region of a kinocilium, peripheral microtubules were connected to the central microtubules by periodic tiny linkers, called radial spokes. These structural features of a kinocilium were identical to those of the tracheal motile cilium.