New line of research on cocaine addiction

Cocaine causes long-lasting alterations in brain activity that may prime the brain for addiction. In May 29 Nature Mark Ungless and colleagues from the University of California, San Francisco, suggest that these changes occur at the first exposure to the drug. They theorise that cocaine could be hijacking normal brain function to reinforce its effects, mimicking the way the brain forms memories and learns from experience.

Using mice they administered either cocaine or a saline solution and analysed the relative activity of AMPA and NMDA dopamine receptors in the ventral tegmental area (VTA). The ratio of activity between these two receptors is a good measure of potentiation.

They found that after just a single dose of cocaine the mice showed significantly increased potentiation in their dopamine neurons compared with those injected with placebo. In addition, the effect lasted for between 5 and 10 days — longer than the drug persisted ...