Figure 8. Thermally evoked hind paw withdrawal latency measured before and after the intrathecal injections of N-methyl-D-aspartate (IT NMDA; 2 nmol) at time = 0 min. Gabapentin (100 mg/kg) was injected intraperitoneally 60 min before the delivery of the IT NMDA. Each line represents the mean +/- SEM of six rats. Repeated measures analysis of variance revealed a significant main effect for time for the group of rats receiving IT NMDA (P > 0.001). In contrast, there was no change in the escape latencies over time for the group receiving IT NMDA + gabapentin. Therefore, at this dose, intraperitoneal gabapentin prevented the hyperalgesia induced by IT NMDA.