A quantitative description of the motor output response of forelimb extensors to linear and angular accelerations is provided. Decerebrate cats were used, since labyrinthine reflexes due to such stimuli are enhanced in this preparation. The data showed that: i) the dynamics of the motor output to stimuli exciting primarily either the saccular or utricular receptors are the same, ii) both canal and otolith outputs are subjected to extensive central processing and iii) canal and otolith outputs are combined in a linear manner to generate the motor output. The problem of the relevance of the observed effects to the problem of postural stabilization is addressed. In brief, the data imply that labyrinthine reflex actions on the forelimbs would be adequate to counteract transient perturbations, but that neck reflexes would be more important in mediating tonic labyrinthine reflexes.
Bibliographical noteFunding Information:
This work was supported by U.S. Public Health Service Grant NS-02567. Computer facilities were made available by the Air Force Office of Scientific Research, AFSC (Grant AFOSR-1221).