02 November 2011
Vol 3, Issue 107

About The Cover

Cover image expansion

ONLINE COVER Smokey Dangers of the Epigenetic Sort. Formed from cigarette smoke, a DNA helix and its attendant nucleosomes symbolize the epigenetic changes caused by nicotine in the brain. Mice treated with nicotine show exaggerated responses to cocaine in the brain's reward centers, an effect likely produced by nicotine-induced changes in nucleosome acetylation, report Levine et al. This mechanism may explain the propensity of young people who smoke to become heavier users of cocaine than those who abstain. [CREDIT: CHRISTOPHER WILLCOX/COLUMBIA UNIVERSITY]