Dopamine D2 receptor gene expression in rat lines selected for differences in voluntary alcohol consumption

A selective breeding program has led to the establishment of the alcohol-preferring AA (Alko, Alcohol) and alcohol-avoiding ANA (Alko, Nonalcohol) rat lines. To reveal putative baseline differences in dopamine receptor gene expression and dopamine receptor binding profile in the AA and ANA rat lines, we assessed striatal D2 mRNA levels in these two rat lines. Autoradiographical studies on dopamine D1 and D2 receptors in the striatum and nucleus accumbens were also performed with [3H]SCH 23390 and [125I]iodosulpiride/[3H]spiperone, respectively. The baseline differences in D1 or D2 receptor binding and D2 receptor gene expression between AA and ANA rat lines are marginal, and are not likely to play a role in the genetic background of the differential alcohol drinking behavior of these rat lines.