Accumulation of activity-regulated cytoskeletal-associated protein (Arc, upper panels) and phosphorylated extracellular signal-regulated kinase (phosphor-ERK1/2, lower panels) in the frontal cortex (left panels) and hippocampus (right panels) of adult animals sacrificed around pnd 90.

<p>Animals were exposed to increasing doses of THC (2.5, 5 and 10 mg/kg) or vehicle from pnd 28 to 45, and to MDMA (10 mg/kg) or saline twice daily every 5 days from pnd 30 to 45 (see text for details). The histograms (mean ± S.E.M.) show the relative change in optical density with respect to the male or female control group. Number of animals per experimental group (n = 4–5). According to ANOVA (P<0.05): (e) significant overall effect of THC within the same sex group; (f) significant MDMA effect among THC-treated animals; (g) significant MDMA effect within the same sex group.