Effects of ropinirole on radial arm maze (RAM). Effects of ropinirole on (a) total accuracy, (b) total number of working memory errors, WME, (c) total number of reference memory errors, RME, (d) mean time spent to complete a trial, (e) % of WMEs and (f) % of RMEs. Effects of ropinirole on horizontal activity according to the locomotor activity study: (g) 0–5 min, (h) 5–10 min and (i) 10–15 min. Asterisks (*) signify a statistically significant effect compared to 0 mg/kg; *p < 0.05, according to Bonferroni post-hoc for multiple comparisons.