The past few years have seen an explosion of heroin abuse and deaths from opiate overdose. But little is known about the molecular underpinnings of heroin addiction. A new study in Biological Psychiatry found that heroin use is associated with excessive histone acetylation, an epigenetic process that regulates gene expression. More years of drug use correlated with higher levels of hyperacetylation. The study, led by Dr. Yasmin Hurd of the Icahn School of Medicine at Mount Sinai, New York, provides the first direct evidence of opiate-related epigenetic alterations in the human brain.
To narrow in on these alterations, first author Dr. Gabor Egervari and colleagues studied postmortem human tissue — a challenging but critical endeavor for understanding the molecular organization of the human brain — from 48 heroin users and 37 controls. They focused on the striatum, a brain region implicated in drug addiction because of its central role in habit formation and goal-directed behavior.