Figure 4: Time course of changes in response code to punctate stimulation. The following response codes were applied: normal sensation (as indicated by 0 in the -axis of the graph); more unpleasant (1), more intense pricking (2), tenderness (3), burning (4), and painful (5). Data are expressed as median values ± interquartile range. Injection of 10−6 M ET-1 induced a significant increase in response code compared to no injection, as indicated by the asterisks (Friedman test, ). Response codes after ET-1 injection were significantly increased after both 10 and 30 min.