Morzorati, Sandra L.Marunde, Rita L.Downey, David2025-09-302025-09-302010Morzorati SL, Marunde RL, Downey D. Limited access to ethanol increases the number of spontaneously active dopamine neurons in the posterior ventral tegmental area of nondependent P rats. Alcohol. 2010;44(3):257-264. doi:10.1016/j.alcohol.2010.02.009https://hdl.handle.net/1805/51244Microdialysis experiments in alcohol-preferring (P) rats have shown that chronic ethanol exposure increases extracellular levels of dopamine in the nucleus accumbens. Since dopamine neuronal activity contributes to the regulation of dopamine overflow in terminal regions, we hypothesized that posterior VTA DA neuron activity (firing frequency, burst activity and/or the number of spontaneously active DA neurons) would be increased in P rats consuming ethanol compared with P rats consuming only water. In vivo electrophysiological techniques were used to evaluate the activity of single dopamine neurons in the posterior VTA. Our findings show that voluntary ethanol intake by nondependent P rats significantly increased the number of spontaneously active dopamine neurons in the posterior VTA compared with P rats that consumed only water. Firing frequency and burst activity did not differ between the two groups. These results suggest that adaptive changes occur in the mesolimbic DA system of nondependent P rats to increase the excitability of posterior VTA DA neurons and enhance DA release from nerve terminals in the nucleus accumbens.en-USPublisher PolicyDopamine neuronsVentral tegmental areaAlcohol-preferring (P) ratsChronic ethanol consumptionSpontaneously active dopamine neuronsArticle