Figure 5.

Focal knockdown of the adenosine A_2A receptors (A_2ARs) in the dorsolateral striatum (DLS) exerts relatively limited effects on habitual behaviors. (a) Representative image shows that A_2ARs were knocked down selectively in the area with the AAV-Cre-zsGreen expression in the DLS of A_2AR^(flox/flox) mice but not in A_2AR^(+/+) mice. The yellow circle depicted the boundary of the AAV-Cre-zsGreen expression and A_2AR knockdown area. (b) Quantitative analysis shows that A_2AR expression was markedly reduced in the AAV-Cre-zsGreen transfected regions of A_2AR^(flox/flox) mice compared with A_2AR^(+/+) mice. (c) Focal A_2AR knockdown in the DLS (n=7) did not affect lever pressing during the acquisition phase compared with their A_2AR^(+/+) controls (n=6) (repeated-measures analysis of variance (ANOVA) revealed no random interval (RI) period × genotype interaction effect: F_5,55=1.234, p>0.05; and no genotype main effect: F_1,11=0.534, p>0.05). (d) There was no genotype × devaluation interaction effect (F_1,11=1.993, p=0.186, repeated-measures ANOVA) for the normalized devaluation test. Both groups similarly showed insensitivity to outcome devaluation (DLS A_2AR knockdown mice: normalized devaluation; t_1,6=0.646, p>0.05; wild-type (WT) mice: normalized devaluation; t_1,5=2.017, p>0.05). Data are presented as the mean±SEM. CRF, continuous reinforcement.