Molecular basis of long-term plasticity underlying addiction

Studies of human addicts and behavioural studies in rodent models of addict ion indicate that key behavioural abnormalities associated with addiction a re extremely long lived. So, chronic drug exposure causes stable changes in the brain at the molecular and cellular levels that underlie these behavio ural abnormalities. There has been considerable progress in identifying the mechanisms that contribute to long-lived neural and behavioural plasticity related to addiction, including drug-induced changes in gene transcription , in RNA and protein processing, and in synaptic structure. Although the sp ecific changes identified so far are not sufficiently long lasting to accou nt for the nearly permanent changes in behaviour associated with addiction, recent work has pointed to the types of mechanism that could be involved.