VESTIBULO-OCULAR RESPONSES DURING THE STATES OF SLEEP IN THE CAT

The vestibulo-ocular response (VOR) was recorded during natural sleep in cats with chronically implanted electrodes. By using a small amplitude sinusoidal head rotation (11° peak-to-peak at 0.4 Hz) which elicited only slow compensatory eye movements, the VOR amplitude was found to decrease steeply (down to 40% or less) during slow-wave sleep. The phase of the VOR with respect to head position remained approximately constant. With a larger amplitude of sinusoidal rotation (320° peak-to-peak at 0.05 Hz) the VOR response included nystagmus. During slow-wave sleep, nystagmus disappeared and the overall amplitude of the response decreased. Simultaneously, the phase of the eye response with respect to head position shifted by up to 90° in advance. During paradoxical sleep, VOR disappeared in all cases and was replaced by randomly occurring bursts of rapid eye movements. These results are discussed in terms of a parametric control model of VOR. © 1978.