Optogenetic interrogations of the neural circuits underlying addiction.

Exposure to addictive drugs can result in maladaptive alterations in neural circuit function. This review highlights recent progress made in identifying the organization, function, and cellular plasticity of the ventral tegmental area (VTA) and nucleus accumbens (NAc), two brain regions strongly implicated in substance use disorders. Emphasis is given to advances made with new research methodologies, particularly optogenetics, which have provided scientists with an unprecedented ability to map neural circuitry and pinpoint drug-induced synaptic modifications. A better understanding of these adaptive events will aid the development of pharmacological treatments for drug addiction and, more generally, further our understanding of motivated behaviors.