1. Department of Chemistry and Biochemistry, University of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, National Institute of Neurological Disorders and Stroke, Anticonvulsant Screening Program, Rockville, Maryland 20852, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, Department of Biochemistry, CWRU Medical School, Cleveland, Ohio 44106, Center for Brain Research, Medical University Vienna, A-1090 Vienna, Austria