Rodd, Zachary A.Bell, Richard L.Oster, Scott M.Toalston, Jamie E.Pommer, Tylene J.McBride, William J.Murphy, James M.2016-02-222016-02-222010-05Rodd, Z. A., Bell, R. L., Oster, S. M., Toalston, J. E., Pommer, T. J., McBride, W. J., & Murphy, J. M. (2010). Serotonin-3 Receptors in the Posterior Ventral Tegmental Area Regulate Ethanol Self-Administration of Alcohol-Preferring (P) Rats. Alcohol (Fayetteville, N.Y.), 44(3), 245–255. http://doi.org/10.1016/j.alcohol.2010.01.002https://hdl.handle.net/1805/8415Several studies indicated the involvement of serotonin-3 (5-HT 3 ) receptors in regulating alcohol- drinking behavior. The objective of this study was to determine the involvement of 5-HT 3 receptors within the ventral tegmental area (VTA) in regulating ethanol self-administration by alcohol-preferring (P) rats. Standard two-lever operant chambers were used to examine the effects of 7 consecutive bilateral micro-infusions of ICS205-930 (ICS), a 5-HT 3 receptor antagonist, directly into the posterior VTA on the acquisition and maintenance of 15% (v/v) ethanol self- administration. P rats readily acquired ethanol self-administration by the 4 th session. The three highest doses (0.125, 0.25 and 1.25 ug) of ICS prevented acquisition of ethanol self- administration. During the acquisition post-injection period, all rats treated with ICS demonstrated higher responding on the ethanol lever, with the highest dose producing the greatest effect. In contrast, during the maintenance phase, the 3 highest doses (0.75, 1.0 and 1.25 ug) of ICS significantly increased responding on the ethanol lever; following the 7-day dosing regimen, responding on the ethanol lever returned to control levels. Micro-infusion of ICS into the posterior VTA did not alter the low responding on the water lever, and did not alter saccharin (0.0125% w/v) self-administration.. Micro-infusion of ICS into the anterior VTA did not alter ethanol self- administration. Overall, the results of this study suggest that 5-HT 3 receptors in the posterior VTA of the P rat may be involved in regulating ethanol self-administration. In addition, chronic operant ethanol self-administration, and/or repeated treatments with a 5-HT 3 receptor antagonist may alter neuronal circuitry within the posterior VTA.en-USPublisher Policyalcohol-preferring ratsserotonin-3 receptorethanol self-administrationventral tegmental areaICS 205-930Article