Long-latency OFF-responses from the human sensorimotor cortex to tetanizing stimulation of thenar muscles

Neuromagnetic recordings revealed a new type of OFF-response from the human sensorimotor cortex 170-235 ms after the end of tetanization of the thenar muscles with 10-240 Hz electrical pulse trains, delivered directly to the thenar eminence or to the median nerve at the wrist. No OFF-responses were discerned when the skin of the thumb was stimulated. The role of muscle afferents in the generation of the OFF-response is discussed.