抄録
Effects of Gentamicin on the vestibular sensory epithelia and the behavior were studied using bull frogs. Gentamicin (80μg) was injected into the perilymphatic cistern for 3 days. The behavior was evaluated in terms of static posture, righting reflex, walking, jumping and swimming. Sensory epithelia of three semicircular canal cristae and the utricular macula were observed using scanning electron microscope.
When the unilateral utricular macula was damaged and the other side was intact or less damaged, the frogs tilted toward the side with severer damage. The angle of head tilt tended to increase according to the degree of morphological asymmetry of the utricular macula. The angle of head tilt increased with the period after injection.
When the bilateral utricular maculae were intact or equally damaged, no tilting was observed. These results indicate that the utricle perceives the gravity to maintain the static posture, and that the degree of utricular dysfunction is assessed by tilting posture.
