Fig. 1. Effect of clonidine on acetylcholine release from lumbar dorsal spinal cord synaptosomes from spinal nerve–ligated (SNL; closed symbols ) or normal ( open symbols ) rats, with ( circle ) or without ( square ) 12 mm KCl stimulation. Each point represents the mean ± SEM of four to five experiments. * P < 0.05 versus normal ( P value for analysis of variance = 0.012). # P < 0.05 versus vehicle ( P value for analysis of variance = 0.008).