DAVID R. SIBLEY, PhD, is a Senior Investigator and Chief of the Molecular Neuropharmacology Section in the National Institute of Neurological Disorders and Stroke, National Institutes of Health. His laboratory is currently investigating the molecular, cellular, and biochemical properties of dopamine receptors and their role in neuronal signaling and pathophysiological states. ISRAEL HANIN, PhD, is Professor and Chair Emeritus in the Department of Pharmacology at Loyola University Chicago. He formerly worked at the National Institute of Mental Health, Laboratory of Preclinical Pharmacology, and at the University of Pittsburgh Department of Psychiatry. Dr. Hanin's research has focused on cholinergic mechanisms, animal models for Alzheimer's disease, and the potential role of glycosaminoglycans in the treatment of Alzheimer's disease. MICHAEL KUHAR, PhD, is currently a Candler Professor and Georgia Research Alliance Professor of Neuropharmacology at the Yerkes Primate Center at Emory University. He previously was a professor in the Neuroscience Department at Johns Hopkins, and a branch chief at the National Institute on Drug Abuse. Dr. Kuhar has published more than 800 articles, abstracts, book chapters, reviews, and patents. PHIL SKOLNICK, PhD, D.Sc. (hon.), is Executive Vice President and Chief Scientific Officer for DOV Pharmaceutical, Inc. He was formerly a Lilly Fellow in Neuroscience and also served as Chief of the Laboratory of Neuroscience, National Institutes of Health.