Effects of operant conditioning and A_2AR activation on the preference of ethanol-containing reward in male C57BL/6J mice. A, Experimental scheme. B, Nose-poking behavior and (C) latency to the magazine during the sessions (n = 14/group). D, We presented tap water, 10S, and 10E10S on each arm of the Y-maze. E, The heat map displays mice tracking patterns for 15 min on the Y-maze. F, Time spent and (G) zone entries of each arm, and (H) total distance traveled for 15 min in the Y-maze (n = 10/group). Data represented as mean ± SEM. *p < 0.05, comparing (B) active and inactive nose-poke, (C) first CRF session, (F, G) the water zone of the same treatment group; ^#p < 0.05 comparing the 10S zone of the same treatment group. B, Two-way repeated-measures ANOVA followed by Bonferroni's multiple-comparisons test, (C, F, G) one-way repeated-measures ANOVA followed by Tukey's multiple-comparisons test (H) one-way ANOVA followed by Tukey's multiple-comparisons test. MT, Magazine training; CGS, 0.1 mg/kg, i.p.