Heinz Steiner is Professor and Chair of the Department of Cellular and Molecular Pharmacology at the Chicago Medical School/Rosalind Franklin University of Medicine and Science in Chicago, Illinois. Dr. Steiner is an expert on the functional organization of the basal ganglia and related brain systems. His research focuses, in particular, on the role of the neurotransmitter dopamine in the regulation of basal ganglia–cortical interactions; his recent investigations examine how chronic enhancement of dopamine actions produce changes in gene regulation, and how these molecular alterations affect basal ganglia function and behavior. He has been the North America Regional Editor for the journal Basal Ganglia since 2011. Kuei Y. Tseng is Associate Professor in the Department of Cellular and Molecular Pharmacology at the Chicago Medical School/Rosalind Franklin University of Medicine and Science in Chicago, Illinois. Dr. Tseng’s research focuses on the neural bases of Parkinson’s disease, particularly the effects of dopamine loss within the cortico–basal ganglia circuitry and the mechanisms underlying information processing in the brains of individuals affected by Parkinson’s disease. He is the editor of two books on the cortex.