ReviewCorticostriatal microRNAs in addiction

•Altered gene expression regulates modifications that drive addiction.•microRNAs are critical regulators of gene expression.•microRNAs in corticostriatal regions may drive development of addiction.•microRNAs may be novel targets for treatment of addiction.

Addiction is a chronically relapsing disorder characterized by compulsive drug use in spite of adverse consequences. Currently, there are very few effective treatments for addiction; in order to develop novel therapies, a clearer understanding of mechanisms underlying addiction is needed. Drugs of abuse induce lasting adaptations in corticostriatal and mesolimbic brain reward circuitry due to long-term alterations in gene expression. microRNAs, a class of non-coding RNAs, are powerful regulators of gene expression that bind to target mRNAs, thereby inhibiting their translation and/or causing degradation. miRNAs are increasingly implicated in gene expression changes underlying normal neuronal function as well as dysfunctions such as addiction and psychiatric disorders. This review summarizes plasticity- and drug-related miRNA expression patterns and functions in the context of corticostriatal circuitry, while proposing future directions that may reveal miRNA-mediated mechanisms regulating addiction-related behaviors in vivo.This article is part of a Special Issue entitled SI:Addiction circuits.