What is the role of the D3 receptor in addiction? A mini review of PET studies with [11C]-(+)-PHNO

The chronic use of drugs, including psychostimulants such as cocaine and amphetamine, has been associated with lowD(2/3) dopamine receptor availability, which in turn has been linked to poor clinical outcome. In contrast, recent studies focused on the D-3 receptor (a member of the D-2-like receptor family) suggest that chronic exposure to stimulant drugs can up-regulate this receptor subtype, which, in preclinical models, is linked to dopamine systemsensitization-a process hypothesized to contribute to relapse in addiction. In this mini review we present recent human data suggesting that the D-3 receptor may contribute to core features of addiction, and discuss the usefulness of the PET imaging probe [C-11]-(+)-PHNO in investigating this question. (C) 2013 Elsevier Inc. All rights reserved.