Paradoxical effects of low dose MDMA on latent inhibition in the rat

► MDMA (6 mg/kg) enhances latent inhibition produced by 10 stimulus pre-exposures. ► MDMA (6 mg/kg) abolishes latent inhibition produced by 40 stimulus pre-exposures. ► HPLC analyses reveal evidence of 5-HT depletion after 2 × 6 mg/kg doses of MDMA.