We will test five normal volunteers before and serially after anesthesia of the median, radial and ulnar nerves at the forearm. Noninvasive magnetic stimulation will be delivered over different scalp positions. If we detect enlargement of the alpha motoneuron pool recruited and the motor representation areas for muscles immediately proximal to the level of anesthesia (biceps, deltoid), it would indicate unmasking of preexistent connections, since no new synapses can be established in such a short time. This would provide valuable information on the mechanisms of reorganization of human central nervous system following deafferentation.
