Figure 2.

Methamphetamine (METH)-seeking behavior is decreased by previous intra-ventral tegmental area (VTA) treatment with SR142948A. (A) Compared with the control group, mice treated with SR142948A exhibited fewer correct side responses on the first day of extinction and in cue-induced reinstatement (“cue-reins.”). (B) No differences between groups were found in the number of wrong-side nose pokes during extinction or cue-induced reinstatement. (C, D) In the progressive ratio test (“prog. ratio”), the number of correct-side responses was decreased in SR142948A-treated mice compared with controls, with no difference between groups in the number of wrong-side responses. (E, F) METH intake and the breakpoint were lower in SR142948A-treated mice compared with controls. Control: n=10 and SR142948A: n=7, Bonferroni posthoc comparisons: *P<.05 and **P<.01 vs CONTROL; ### P<.01 vs baseline (BL, last fixed ratio 3 [FR3] session).