Effect of pretreatment with a single low dose of MDMA (3 mg/kg, i.p.) 96 h before on MDMA (12.5 mg/kg, i.p.)-induced changes in IL-1β and IL-1ra levels in frontal cortex. (A) Pretreatment with low dose MDMA attenuated the increase in IL-1β produced by neurotoxic MDMA 3 h later. (B) Pretreatment with low dose MDMA produced an increase in IL-1ra levels 1 h after neurotoxic MDMA. Results shown as mean ± s.e.mean, n = 7-8. Different from saline-treated controls: *P < 0.05. Different from neurotoxic MDMA: ΔP < 0.05, ΔΔP < 0.01. One-way ANOVA followed by Newman-Keuls test. Levels of the cytokines in animals treated only with low dose MDMA were not included but were considered to be similar to those observed at the 96 h time point of Figure 3.