Fig. 4.
MDMA lost its ability to increase CART mRNA expression in the NAc of 5-HT4R KO mice. Using QR-PCR (A and B), in eight MDMA-treated WT mice, the levels of CART mRNA were higher than in seven saline-treated WT animals (F1,13 = 4.7, P < 0.05). This effect was not apparent in 5-HT4R KO mice (F1,10 = 0.8, n = 5–7). A significant difference between NaCl and MDMA is noted (*, P < 0.05), and a significant genotype × treatment interaction is marked (# P < 0.05). Using in situ hybridization (C–F), MDMA-induced increases in CART mRNA levels in the NAc were also observed in coronal brain sections in WT (C and D), but not in KO mice (E and F). (Scale bar: 700 μm.)