Brain protein holds the key for understanding drug addiction
19 January 2010
Experts from the Institute of Psychiatry, King’s College London, with colleagues from Brazil, have identified that variations in a neurotransmitter receptor gene GABRA-A2 are associated with cocaine addiction.
Professor Gunter Schumann at the Institute of Psychiatry said: 'In a large sample of cocaine addicts and healthy non-drug taking controls we identified a genetic profile which protects against the use of cocaine and reduces the risk of becoming cocaine addicted by about 50%.'
The research, published in Proceedings of the National Academy of Sciences of the United States of America today, was led by University of Sussex who in animal studies have discovered the relevance of this gene for cocaine addiction.
University of Sussex had discovered that a receptor protein for the chemical messenger GABA played a special role in how reward motivations were prioritized in the brain. The removal of the protein showed a lack of the behavioural changes which come about with persistent cocaine use, so reward-seeking towards drugs at the expense of natural rewards did not develop, even though the stimulant effects of cocaine were exhibited.
Dr Gerome Breen from the Institute of Psychiatry said: 'hile the evidence is statistically strong, the finding is not of predictive value - we cannot use testing of this gene to predict who will or will not become a cocaine addict. However, it does suggest that drugs targeting this receptor may be useful in treating cocaine addiction in humans and should be investigated.'
Cocaine effects on mouse incentive-learning and human addiction are linked to α2 subunit-containing GABAA receptors: http://www.pnas.org/content/early/2009/12/29/0910117107.abstract