Glycocalyx and ciliary interconnections in bullfrog vestibular end organs: normal structure and changes after incubation in frog Ringer's solution.

The ultrastructure of ciliary interconnecting systems as well as changes after incubation in frog Ringer's solution of the bullfrog vestibular end organs were investigated by using a scanning electron microscopy. The plasma membrane of the sensory hairs showed rather rough appearance. Side links emerged from the plasma membrane and tightly connected neighboring cilia. The tip links stretched from the tips of the stereocilia to their taller neighbors. These tip links were arranged in a same direction towards the kinocilium. These findings indicate that the side links may keep the cilia arranged in a bundle and the tip links may be involved in sensory cell transduction system. Changes in the surface texture and ciliary interconnecting systems were detected 2 hrs after incubation in frog Ringer's solution. Such changes included an increase in granularity of the surface membrane, fracturing and disappearance of all types of ciliary interconnections, especially side links. The tip links were more durable than side links. This indicates that the physiological studies of bullfrog hair bundle are justified across a 1-hr interval from the time the temporal bones are removed from the animal.