Addiction: a loss of plasticity of the brain?

Why is it that only some drug users become addicts? This is the question that has been addressed by the teams of Pier Vincenzo Piazza and Olivier Manzoni, at the Neurocentre Magendie in Bordeaux (Inserm unit 862). These researchers have just discovered that the transition to addiction could result from a persistent impairment of synaptic plasticity in a key structure of the brain. This is the first demonstration that a correlation exists between synaptic plasticity and the transition to addiction. The results from the teams at Neurocentre Magendie call into question the hitherto held idea that addiction results from pathological cerebral modifications which develop gradually with drug usage. Their results show that addiction may, instead, come from a form of anaplasticity, i.e. from incapacity of addicted individuals to counteract the pathological modifications caused by the drug to all users. This research is published in the journal Science on 25 June 2010.