Changes in methamphetamine-induced rotational behaviour in 6-OHDA-injected rats that had been co-injected or not co-injected with DJ-1-binding compound-23. Rats were simultaneously injected with the vehicle (each n = 4) or 32 nmol of 6-OHDA (each n = 6) in the presence (n = 6) or absence (n = 4) of 4 nmol of DJ-1-binding compound-23 (comp-23) in a final volume of 4 μL sterilized physiological saline containing 0.02% ascorbic acid and 1% DMSO. Rotational behaviour was assessed at 7 days after 6-OHDA injection. The number of full body turns in the ipsilateral direction was counted for 70 min after the administration of methamphetamine (2.5 mg/kg, i.p.). Each value is the mean ± SEM. Significance (Bonferroni/Dunn post hoc comparisons after ANOVA in A; Student's t-test in B): *P < 0.05, **P < 0.01, ***P < 0.001 vs. vehicle control rats. †P < 0.05, ††P < 0.01, †††P < 0.001 versus 6-OHDA-injected rats.