Zapping brain with magnets may cure cocaine addiction

Stimulating a certain part of the brain with magnets can wipe away cocaine addiction, scientists claim.

Researchers at the National Institutes of Health (NIH) and the Ernest Gallo Clinic and Research Center at University of California, San Francisco (UCSF) have shown that by stimulating a part of the brain with laser light, they can wipe away addictive behaviour in rats - or conversely turn non-addicted rats into compulsive cocaine seekers.

"When we turn on a laser light in the prelimbic region of the prefrontal cortex, the compulsive cocaine seeking is gone," said Antonello Bonci, scientific director of the intramural research programme at the NIH's National Institute on Drug Abuse (NIDA), where the work was done.

The study demonstrates the central role the prefrontal cortex plays in compulsive cocaine addiction. It also suggests a new therapy that could be tested immediately in humans, said Billy Chen of NIDA, the lead author of the study.

Any new human therapy would not be based on using lasers, but would most likely rely on electromagnetic stimulation outside the scalp, in particular a technique called transcranial magnetic stimulation (TMS), researchers said.

To test whether altering the activity in this brain region could impact addiction, Chen and his colleagues employed a technique called optogenetics to shut the brain activity on and off using a laser.

First they took light-sensitive proteins called rhodopsins and used genetic engineering to insert them into neurons in the rat's prefrontal cortex. Activating this region with a laser tuned to the rhodopsins turned the nerve cells on and off.

Turning on these cells wiped out the compulsive behaviour, while switching them off turned the non-addicted ones into addicted, researchers found.

What's exciting, said Bonci, is that there is a way to induce a similar activation of the prelimbic cortex in people through a technique called transcranial magnetic stimulation (TMS), which applies an external electromagnetic field to the brain and has been used as a treatment for symptoms of depression.

The study was published in the journal Nature.