Ethanol Is Self-Administered Into the Nucleus Accumbens Shell, But Not the Core: Evidence of Genetic Sensitivity
Article first published online: 17 SEP 2009
Copyright © 2009 by the Research Society on Alcoholism
Alcoholism: Clinical and Experimental Research
Volume 33, Issue 12, pages 2162–2171, December 2009
How to Cite
Engleman, E. A., Ding, Z.-M., Oster, S. M., Toalston, J. E., Bell, R. L., Murphy, J. M., McBride, W. J. and Rodd, Z. A. (2009), Ethanol Is Self-Administered Into the Nucleus Accumbens Shell, But Not the Core: Evidence of Genetic Sensitivity. Alcoholism: Clinical and Experimental Research, 33: 2162–2171. doi: 10.1111/j.1530-0277.2009.01055.x
- Issue published online: 19 NOV 2009
- Article first published online: 17 SEP 2009
- Received for publication February 9, 2009; accepted July 29, 2009.
- Intracranial Self-Administration;
- Nucleus Accumbens;
- Alcohol-Preferring Rats;
Background: A previous study indicated that selectively bred alcohol-preferring (P) rats self-administered ethanol (EtOH) directly into the posterior ventral tegmental area at lower concentrations than Wistar rats. The present study was undertaken to determine involvement of the nucleus accumbens (Acb) with EtOH reinforcement, and a relationship between genetic selection for high alcohol preference and sensitivity of the Acb to the reinforcing effects of EtOH.
Methods: Adult P and Wistar rats were assigned to groups that self-infused 0 to 300 mg% EtOH into the Acb shell (AcbSh) or Acb Core (AcbC). Rats were placed into 2-lever (active and inactive) operant chambers and given EtOH for the first 4 sessions (acquisition), artificial cerebrospinal fluid (aCSF) for sessions 5 and 6 (extinction), and EtOH again in session 7 (reinstatement). Responding on the active lever produced a 100-nl injection of the infusate.
Results: Alcohol-preferring rats self-infused 75 to 300 mg% EtOH, whereas Wistar rats reliably self-infused 100 and 300 mg% EtOH into the AcbSh. Both P and Wistar rats reduced responding on the active lever when aCSF was substituted for EtOH, and reinstated responding in session 7 when EtOH was restored. EtOH was not self-infused into the AcbC by P or Wistar rats.
Conclusions: The present results indicate that the AcbSh, but not AcbC, is a neuroanatomical structure that mediates the reinforcing actions of EtOH. The data also suggest that, compared to Wistar rats, the AcbSh of P rats is more sensitive to the reinforcing effects of EtOH.