From the Laboratory of Neurophysiology (Drs. Pullman and Watts), National Institute of Mental Health, and the Experimental Therapeutics Branch (Drs. Juncos and Chase) and Human Motor Control Section, Medical Neurology Branch (Dr. Sanes), National Institute of Neurological and Communicative Disorders and Stroke, National Institutes of Health, Bethesda, MD.(1988-02時点)