[Interaction of the motor centers in posture-evoked asymmetry].

The EMG of hindlimb muscles was studied in spinal cats in resting and in evoked responses prior to and after modelling posture asymmetry with brain extracts obtained from donor rats whose cortical and cerebellar motor areas were partially lesioned. After the extract administration, slow and diverse changes occurred in the EMG amplitude whereas a constant level of activity was only maintained for limited periods (4-10 min). The most frequent patterns of interaction among hindlimb muscles were revealed and the character of evoked responses was shown to depend on the initial spontaneous pattern. The different EMG patterns in spinal animals seem to be due to a "mosaic" effects of interneurons, the posture of asymmetry being related to disturbance of interaction among the interneurons.