Against addiction: light at the end of the tunnel?

摘要

Drug addiction is the among the most costly brain diseases, totaling 57 billion euros in direct and indirect costs in Europe alone. It is a disease without cure. Although it is impossible to say how far off we are from seeing the light at the end of the tunnel, substantial advances have been made over the last decade.The emerging model that addiction is a disease of 'learning gone wrong' is now widely accepted (Redish et al. 2008). Of particular interest in this context is the observation that all addictive drugs, and only addictive drugs, drive specific forms of synaptic plasticity in the mesolimbic system. Sometimes also referred to as the reward system, the mesolimbic system originates in the ventral tegmental area and projects to the nucleus accumbens (NAc). In a paper in a recent issue of The Journal of Physiology D'Ascenzo et al. (2009) point to an interesting mechanism for how the excitability of neurons in the NAc is enhanced by type 5 metabotropic glutamate receptors (mGluR5).