ROLE OF SEMICIRCULAR CANALS IN POSITIONAL ALCOHOL NYSTAGMUS.

Following unilateral labyrinthectomy or inactivation of one horizontal semicircular canal in cats, a horizontal positional nystagmus was observed when the cat, after ingesting alcohol, was held with the head up or with the head down. This nystagmus was toward the operated ear in the head-up position and away from the operated ear in the head-down position. It disappeared following inactivation of the horizontal canal of the other ear. In cats with both horizontal canals discretely inactivated, there was no horizontal alcohol nystagmus in any position, but the vertical and rotary components of positional alcohol nystagmus were still present. It was concluded that positional alcohol nystagmus is initiated by the action of gravity on receptors of the semicircular canals. No conclusion could be drawn concerning the site or mechanism of the action of alcohol. (Author)
Pub. in American Journal of Physiology v208 n6 p1065-70 Jun 1965. (Copies not available to DDC or Clearinghouse customers).