Effects of chronic ethanol intake on the expression of monoamine oxidase (MAO) in the brain prefrontal cortex of wild type (Klf11+/+) and knockout (Klf11−/−) mice. Mice were fed an ethanol diet or control diet for 28 days. (A) The mRNA (a) and enzyme activity (b) of MAO A and (B) the mRNA (a) and enzyme activity (b) of MAO B in the prefrontal cortex were examined by Real-time RT-PCR and catalytic activity assays, respectively. Data represent the mean ± SEM of 10 mice (n = 10) in each group. Aa, p<0.02 (lanes 3 vs. 1 and lanes 4 vs. 2); Ab, p<0.07 (lanes 4 vs. 2); Ba, p<0.02 (lanes 3 vs. 1) and p<0.05 (lanes 4 vs. 2); Bb, p<0.02 (lanes 3 vs. 1)