Effects of stimulation of cortical motor points in dogs after hemisection of the spinal cord

Summary

The effects of electric stimulation of the motor points of the cortex were studied in dogs following laroral hemisection of the spinal cord at the level of 2nd–3rd cervical segments. Chronic experiments were staged on 6 adult dogs without anesthesia. Superficial silver electrodes were implanted into trephined openings in the cranium over the motor area of the cortical representation of the fore limbs; this was done for stimulation of the motor points of the cortex. Stimulation of the cortex was first carried out prior to hemisection of the spinal cord, then 1–5 months later. For the first time it was shown that after the spinal cord hemisection it was possible to provoke movement in the affected extremity by stimulation of the corresponding motor points in the cerebral cortex. Such movement may be induced about 3–4 weeks after spinal cord hemisection, i.e., 2 to 3 days before the extremity begins actively to participate in standing and walking.