FIGURE 9.

Comparison of nociceptive responses (mechanical hyperalgesia) induced in mice injected with Yoda1, capsaicin and vehicle alone. (A) A schematic showing sites of injection and behavioral testing in the mouse hind foot. For injection, a 30-gauge needle was inserted at the heel of the foot (X) and advanced to the injection site (I), where a 5 μl intradermal injection of Yoda1 (5 nanomole), capsaicin (15 nanomole) or vehicle alone was carried out. Foot withdrawal frequencies in response to von Frey filament stimuli were measured at the primary site (P) for hyperalgesia and at the secondary site (S) for hyperalgesia. (B) Primary and (C) secondary mechanical hyperalgesia measured in response to Yoda1 and vehicle alone. (D) Primary and (E) secondary mechanical hyperalgesia measured in response to capsaicin and vehicle alone. The data points represent mean ± SEM for 4–5 mice under each condition. The Mann–Whitney U test was used to compare Yoda1 or capsaicin against vehicle alone at each time point.