Fig. 1.

Time-effect curves of intrathecal nociceptin/orphanin FQ (N/OFQ) for flinching responses in the formalin test. X-axis: time (min) after formalin injection. Y-axis: number of flinches for each 5-min session. Different doses of NC and saline (as a vehicle) were administered 10 min before formalin injection. I.t. administration of N/OFQ dose-dependently attenuated formalin-induced flinching responses (p<0.05). Each value represents mean±SD (n=8). Symbols represent different dosing conditions for each panel. ED₅₀ values (Cl₉₅ values) of N/OFQ were 5.3 (4.2-6.4) nmol in dose-response curves and 4.3 (3.2-5.4) nmol and 6.6 (4.8-8.3) nmol for phase I and phase II, respectively. SD, standard deviation.