Dopamine Mechanisms and Cocaine Reward

• Published in: International Review of Neurobiology Vol. 62; pp. 45 - 94
• Main Authors: Ikegami, Aiko, Duvauchelle, Christine L.
• Format: Book Chapter Journal Article
• Language: English
• Published: United States Elsevier Science & Technology 2004
• Subjects: Animals; Brain - drug effects; Brain - physiology; Cocaine - pharmacology; Cocaine-Related Disorders - physiopathology; Dopamine - physiology; Dopamine Uptake Inhibitors - pharmacology; Humans; Neurology & clinical neurophysiology; Neurosciences; Reward
• ISBN: 9780123668622; 012366862X
• ISSN: 0074-7742; 2162-5514
• DOI: 10.1016/S0074-7742(04)62002-2

This chapter focuses on the dopamine (DA) mechanisms and cocaine rewards. Cocaine is rapidly absorbed through many routes of administration and enters the brain, where DA neural pathways are the primary sites for its effects. Increased DA levels resulting from cocaine binding to the DA transporter (DAT) is associated with the rewarding effects of cocaine. Even in the absence of DAT, cocaine increases extracellular DA levels and retains reinforcing properties. Cocaine blocks Na+/Cl- dependent plasma membrane transporters for monoamine neurotransmitters including dopamine (DA), serotonin (5-hydroxytryptamine, 5-HT), and norepinephrine (NE). Cocaine heterogeneously influences extracellular DA levels in the sub-territories of the nucleus accumbens (NAcc). The prefrontal cortex (PFC) is involved in many types of complex behavior including response inhibition, order of events recall, spatial orientation, social and affective behavior, behavioral spontaneity, and associative learning. Damage to the PFC can result in impulsive personality disorder. Too much or too little DA transmission in the PFC is associated with impaired cognitive processes. Deeper understanding of cocaine abuse and addiction comes about by continuing to expand cocaine research beyond the pharmacological effects at neural terminal regions. Because the relapse of cocaine use is a prominent obstacle to overcome in recovering individuals, mechanisms underlying relapse behavior have become a major focal point of scientific inquiry.