Adenosine transporter ENT1 regulates the acquisition of goal-directed behavior and ethanol drinking through A2A receptor in the dorsomedial striatum

• Published in: The Journal of neuroscience Vol. 33; no. 10; pp. 4329 - 4338
• Main Authors: Nam, Hyung Wook, Hinton, David J, Kang, Na Young, Kim, Taehyun, Lee, Moonnoh R, Oliveros, Alfredo, Adams, Chelsea, Ruby, Christina L, Choi, Doo-Sup
• Format: Journal Article
• Language: English
• Published: United States Society for Neuroscience 06.03.2013
• Subjects: Alcohol Drinking - genetics; Alcohol Drinking - metabolism; Analysis of Variance; Animals; beta-Galactosidase - metabolism; Choice Behavior - drug effects; Choice Behavior - physiology; Conditioning, Operant - drug effects; Conditioning, Operant - physiology; Corpus Striatum - drug effects; Corpus Striatum - physiology; CREB-Binding Protein - genetics; CREB-Binding Protein - metabolism; Cyclic AMP-Dependent Protein Kinases - metabolism; Equilibrative Nucleoside Transporter 1 - genetics; Equilibrative Nucleoside Transporter 1 - metabolism; Gene Expression Regulation - drug effects; Gene Expression Regulation - genetics; Goals; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Mice; Mice, Inbred C57BL; Mice, Transgenic; Receptor, Adenosine A2A - metabolism; Reinforcement Schedule; Signal Transduction - drug effects; Sucrose - administration & dosage; Sweetening Agents - administration & dosage; Triazines - pharmacology; Triazoles - pharmacology
• ISSN: 1529-2401; 0270-6474; 1529-2401
• DOI: 10.1523/JNEUROSCI.3094-12.2013

Adenosine signaling has been implicated in the pathophysiology of many psychiatric disorders including alcoholism. Striatal adenosine A2A receptors (A2AR) play an essential role in both ethanol drinking and the shift from goal-directed action to habitual behavior. However, direct evidence for a role of striatal A2AR signaling in ethanol drinking and habit development has not been established. In the present study, we found that decreased A2AR-mediated CREB activity in the dorsomedial striatum (DMS) enhanced initial behavioral acquisition of goal-directed behaviors and the vulnerability to progress to excessive ethanol drinking during operant conditioning in mice lacking ethanol-sensitive adenosine transporter ENT1 (ENT1(-/-)). Using mice expressing β-galactosidase (lacZ) under the control of seven repeated CRE sites in both genotypes (CRE-lacZ/ENT1(+/+) mice and CRE-lacZ/ENT1(-/-) mice) and the dominant-negative form of CREB, we found that reduced CREB activity in the DMS was causally associated with decreased A2AR signaling and increased goal-directed ethanol drinking. Finally, we have demonstrated that the A2AR antagonist ZM241385 dampened protein kinase A activity-mediated signaling in the DMS and promoted excessive ethanol drinking in ENT1(+/+) mice, but not in ENT1(-/-) mice. Our results indicate that A2AR-mediated CREB signaling in the DMS is a key determinant in enhancing the development of goal-directed ethanol drinking in mice.