Effect of cupula shrinkage on the semicircular canal activity.
CONCLUSIONS
With half-sized cupula, the semicircular canal nerve potentials decreased under slow stimulus, thus potentially leading to reduced caloric response. This also suggests that shrunken cupula may cause dizziness because of its hypermobility.


OBJECTIVE
To examine the physiological effect of half-sized cupula on the semicircular canal nerve potential.


METHODS
The isolated cupula of the bullfrog was sectioned in half with fine scissors and was replaced on the crista. Mechanical endolymphatic flow and slow and fast stimuli were delivered and the evoked action potentials were recorded.


RESULTS
The cupula was successfully sectioned in half and was replaced on the crista. With the half-sized cupula, the action potentials became smaller under slow stimulus than under fast stimulus.
Iimura
Youichi
Y
Department of Otolaryngology, Tokyo Medical University, Japan.
Suzuki
Mamoru
M
Otsuka
Koji
K
Inagaki
Taro
T
Konomi
Ujimoto
U
Shimizu
Shigetaka
S
D000818:Animals; D004710:Endolymph / Q000502:physiology; D005071:Evoked Potentials / Q000502:physiology*; D011892:Rana catesbeiana; D012665:Semicircular Canals / Q000294:innervation / Q000502:physiology*