Fig. 2. Effect of intravenous (iv) injection of 10–30 mg/kg pregabalin (n = 8) or R -3-isobutylgaba (n = 6) on the withdrawal latency of the left hind paw in response to radiant heat stimulation. The timing of three injections is indicated by arrows. Data are presented as mean ± SEM. *P < 0.05 versus pretreatment control.