'Drug binge' mice reveal why cravings linger / New Scientist, 9 April 2008
http://digbig.com/4wsex
"Drug cravings can persist long after an addict is "clean", and often cause relapse. Now we are closer to understanding why, with a detailed picture of how the highly addictive drug methamphetamine causes long-lasting changes in key communication pathways between neurons in the brain."