MDMA alone affects sensorimotor and prepulse inhibition responses in mice and rats: tips in the debate on potential MDMA unsafety in human activity

Purpose: MDMA is a psychoactive drug that has been increasingly abused worldwide, due to its entactogenic properties. However, concerns on its safety exist, particularly regarding its effects on attentional skills and performance. Evidence from the literature shows contrasting effects of MDMA. It generally acts as a pshychomotor stimulant, thus improving arousal and psychomotor function. However, MDMA has been demonstrated to negatively influence other skills. Consequently, human activities that require alertness, and accurate and quick reflexes (i.e. driving, operations at the workplace, etc.) could be negatively affected. In the present study, the effect of MDMA (0.1–20 mg/kg, intraperitoneally) on sensorimotor and startle/prepulse inhibition responses was evaluated in a controlled rodent experimental setting. Methods: Sensorimotor studies, evaluation of visual, acoustic, and tactile responses, evaluation of spontaneous locomotion, startle and repulse inhibition analyses were performed in an experimental controlled rodent model (rats and mice), following the administration of MDMA (0.1–20 mg/kg) intraperitoneally. Results: Our findings show that all the MDMA-treated animals had impaired sensorimotor and prepulse inhibition responses compared to the control subjects at the early (5, 30 and 60 min) testing time points while all the effects disappeared, respectively, 6, 16 and 24 h post-MDMA treatment. Conclusions: Within the ongoing debate on the safety of recreational abuse of MDMA, our results reveal acute prominent changes in sensorimotor and attentional performance, sensor response to external stimuli, and locomotor activity due to a single administration of a dose of MDMA (corresponding to a dose producing in humans both ‘desirable’ entactogenic effects and physiological adverse effects).