The behaviour of lateral vestibular neurons during walk, trot and gallop in acute precollicular decerebrate cats

Abstract

During controlled locomotion in acute decerebrate cats, discharge characteristics of 90 Deiters' neurons were analysed. Representative Deiters' neurons changed their discharge from a tonic pattern (loco-motor-unrelated) during slow walk to a phasic pattern (locomotor-related) during fast walk. Bursting discharge of these units was phase-locked with the bursting EMG activity of either the left or the right hindlimb extensor muscle. During trot, the same Deiters' neurons discharged twice in a single step cycle, and each bursting discharge was phase-locked with the bursting EMG activity of the left and the right hindlimb extensor muscles. During gallop, in which bursting EMG activities of bilateral hindlimb muscles appeared more or less in phase, such bursting discharges of the Deiters' neurons fused each other, thus being phase-locked with the bursting EMG activity. There were also activities of Deiters' neurons recruited at each transitional phase of locomotion from slow walk to fast walk, fast walk to trot and trot to gallop. These recruited Deiters' neurons either changed their discharge patterns in a sequence as described above or maintained a tonic pattern with an increase in the firing frequency in relation to the changes in the pattern of locomotion. © 1988, Elsevier B.V. All rights reserved.