Fig. 2.

(A) Time course of paw withdrawal frequency to cold stimuli. The response frequencies were measured before (Pre) and after oral administration of distilled water (DW), levodopa 10 mg/kg (L-DOPA10), levodopa 30 mg/kg (L-DOPA30), levodopa 50 mg/kg (L-DOPA50), levodopa 70 mg/kg (L-DOPA70), and levodopa 100 mg/kg (L-DOPA100). The results are expressed as mean±SE (n=10 in each group). ^*p<0.05, ^†p<0.01, ^‡p<0.001, ^§p<0.0001 significantly different from the DW group. (B) Dose-response curve from the peak effects of percentage maximal possible effect (%MPE) for cold anti-allodynia in the levodopa groups. This shows a dose-dependent cold anti-allodynic effect. Each line represents mean±SE for 10 rats. Doses (mg/kg) are represented logarithmically on the x-axis and peak %MPE is represented on the y-axis. ^*p<0.05 vs. DW, ^†p<0.01 vs. DW, ^‡p<0.001 vs. DW.