Antagonists (1) of alpha-7 nicotinic receptors are proving to be new and interesting molecural targets in the development of new medicines against cannabis addiction. The result comes from a study led by a team from the Institut de physiologie et biologie cellulaires (IPBC, CNRS /  University of Poitiers), in collaboration with the University of Cagliari (Italy) and the National Institute on Drug Abuse (USA). The researchers demonstrated that the antagonist of the alpha-7 nicotinic receptor, methyllycaconitine (MLA), can counteract the reinforcing and discriminating effects of the main constituent of cannabis, delta-9-tetrahydrocannabinol (THC) or of a synthetic cannabinoid agonist (2). All addictive substances affect the body's reward system. Once activated, this system produces a feeling of physical and mental satisfaction, which people who are addicted to the substance try to reproduce. Thus this activation plays a major role in the development of addiction. The team from IPBC has just shown that MLA prevents THC from activating the system, through doses which are neither toxic nor sedative. Furthermore, as opposed to alpha-7 nicotinic antagonists, non-alpha-7 antagonists have no effet on this discrimination of cannabinoids or on the activation of reward system. While physical addiction to cannabis can be weak, psychological addiction can nonetheless still require medical intervention. The discovery of these new molecular targets which reduce the psychotropic effects of marijuana are essential to the development of effective treatments.