Understanding relapse

A study published this week in Nature Neuroscience provides causal evidence that the propensity to relapse back to heroin use is controlled by a small subset of medial prefrontal cortex (mPFC) neurons. These findings using rodent models of addiction could be important in understanding how to treat human addicts to lessen the likelihood of relapse.

Both rodents and humans form an association between addictive substance use and the context in which the addictive drugs were taken. Addicts are prone to relapse when re-exposed to the drug-associated contextual cues.

Yavin Shaham and colleagues show that a small group of neurons in mPFC exhibit higher activity when rats previously trained to self-administer heroin are re-introduced to the context in which drug was taken. By administrating a pharmacological agent that selectively disrupts these activated neurons, the scientists also show that inactivating these specific mPFC neurons can lessen the reinstatement of heroin-seeking behavior in relapsing rats.