Think of the brain as a car park where every space is tailored to an individual's car. Chemicals – called neurotransmitters – that stimulate the tangle of neurons between our ears can use their space, and theirs alone, in order to park and do their job. But it's possible for another similarly shaped molecule to arrive before them and block them from going to work. This can be dangerous – many poisons steal neurotransmitters' parking spots – but it could also be a valuable way of treating drug addiction. Boosting the levels of a chemical that obstructs the route cannabis takes to stimulate the brain's reward centre makes addicted animals less likely to relapse and take the drug. The research opens up the possibility of new treatment methods for cannabis addicts, who are almost as numerous in the USA as heroin and cocaine addicts combined.
Written by Jan Piotrowski