Original articleDifferent Adaptations in Ventral Tegmental Area Dopamine Neurons in Control and Ethanol Exposed Rats After Methylphenidate Treatment
Section snippets
Prenatal Ethanol Treatment and Cross Fostering
The procedures of prenatal ethanol treatment and cross fostering are described in detail in previous studies (Choong and Shen 2004a, Choong and Shen 2004b). Time-pregnant rats were administered ethanol via intragastric intubation between gestation day 8 and 20 with a daily dose of 0 g/kg or 6 g/kg ethanol (20% wt/vol in .9% saline) during weekdays by two intubations at 0 g/kg or 3 g/kg. A single daily dose of 0 g/kg or 4 g/kg ethanol was given during weekends due to limited resources. The 0
Results
Repeated MPH treatment differentially altered VTA DA neuron population activity in control and PE animals. In the control group, repeated MPH treatment lead to a significant 53% increase in VTA DA neuron population activity 1 day posttreatment (n = 10) when compared with that observed in repeated saline-treated control animals recorded 1 day posttreatment (n = 11; Fisher LSD post hoc test following one-way ANOVA, p < .01; Figure 1A). The increase was not observed 7 (n = 11) or 30 to 60 days (n
Discussion
In the present study, we demonstrated that repeated MPH treatment at a low, clinically relevant dose (1 mg/kg, SC; Kuczenski and Segal 2002) during adolescence produced long-lasting adaptational changes in the excitability in VTA DA neurons after cessation of treatment in adulthood. These changes were distinctly different in control and PE animals. In control animals, MPH treatment led to an initial increase in the population activity 1 day posttreatment, which subsided 7 and 30 to 60 days
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