[Role of the commissural channels of the somatosensory system in the conduction of feedback signals during the control of voluntary movements].

The time-course of formation of the conditioned defence reflex and electromyograms of the working forelimb were studied on cats with classical and commissural somatosensory pathways transections. It was established that exclusion of the classical somatosensory projections only reduces the rate of the skill formation that is related to the possibility of conducting feedback signals via the remaining commissural pathways. However, the commissural channel in question is not effective enough, since its isolated functioning is accompanied by an increase in the duration of instrumental movement. The combined transection of the classical and commissural somatosensory pathways excludes the possibility of formation of the conditioned reflex on the "deafferented" limb. The lack of direct visual control over the moving forelimb does not essentially affect the behavioral and electromyographic data.