Effect of intrathecal SP-CTA on thermal nociception in rats. A. SP-CTA dose response relationship. Rats (N = 10/dose) received intrathecal injections of the indicated doses of SP-CTA in 20 μl of saline. Twenty four hours following the injections the animals were tested for thermal nociception using a Hargreaves apparatus . Asterisks indicate p < 0.05 one way ANOVA (F = 5.527, df = 49) followed by Dunnett's test when compared to the saline treated animals. B. Time course of intrathecal SP-CTA on thermal nociception. Rats (N = 20) were injected intrathecally with 1 μg of SP-CTA in 20 μl of saline. The animals were tested for thermal nociception at the times indicated. Zero represents the day of injection. Data are presented as means ± SEM. Asterisk indicates p < 0.05 repeated measures ANOVA (F = 5.06, df = 99) followed by Dunnett's test when compared to the zero time point.