Postsynaptic inhibitions of trigeminal and lumbar motoneurons from the superficial radial nerve in the cat.

Natural stimulation of the skin surface by pressuring or electrical stimulation of the cutaneous nerve may induce 'hypnotic', inactive or sleep state in the animal, besides evoking the segmental reflex activities 2.10,16,21,27). In this inhibitory influence, not only the motor activity but also the sympathetic nervous activity, as is indicated by the blood pressure or sweating 13.27), is involved. In anesthetized cat the spindle burst wave can be triggered in the neocortex from the cutaneous nerves1). This associates with the behavioral silence in case of the intact unanesthetized cat21). It is further known that, when the spindle burst appears in the neocortex, there is a depressive influence to the hind limb fusimotor neurons11). To investigate this inhibitory effect on the motor activity, the intracellular technique was applied in the present study to the trigeminal and lumbar motoneurons of the decerebrate cat.