[Participation of vertical semicircular canals in the vestibulo-oculomotor response to the horizontal rotation test]

The horizontal rotatory test was shown to elicit in rabbits a complex three-plane vestibular oculomotor response with rotatory nystagmus (RN) in sagittal plane. The leftward accelerating rotation caused the clockwise RN of the right eye; during decelerating rotation the RN was directed counterclockwise. Its frequency may differ from that of the horizontal nystagmus. The cupulo-endolymphatic displacements seem to occur not only in the horizontal canal, i.e. in the plane of rotation, but also in the vertical canals as a result of a hypothetical hydrodynamic interaction between the canals. The displacements in the anterior and the horizontal canals of the labyrinth were analogous, whereas that in the posterior canal was of the opposite direction. That suggests that the utriculofugal displacements in the horizontal and the anterior canals are accompanied by an utriculofugal displacement in the posterior canal, and vice versa.