LONG-TERM REORGANIZATION OF HUMAN MOTOR CORTEX DRIVEN BY SHORT-TERM SENSORY STIMULATION

Removal of sensory input can induce changes in cortical motor represen tation that reverse when sensation is restored. Here we ask whether ma nipulation of sensory input can induce long-term reorganization in hum an motor cortex that outlasts the initial conditioning. We report that for at least 30 minutes after pharyngeal stimulation, motor cortex ex citability and area of representation for the pharynx increased, while esophagus representation decreased, without parallel changes in the e xcitability of brainstem-mediated reflexes. Therefore increased sensor y input can drive long-term cross-system changes in motor areas of the cerebral cortex, which suggests that sensory stimulation might rehabi litate dysphagia, a frequent consequence of cerebral injury.