Laser Light 'Zaps' Away Cocaine Addiction: New Way to Lose Bad Habits

There's no easy way to get over an addiction. It can take months or even years to get rid of a habit, such as smoking or abusing cocaine. Yet there may be an easier way to cope with an addition in the future. A new study reveals that by stimulating one part of the brain with laser light, researchers can "zap" away an addiction.

Cocaine abuse is a major public health issue in the United States. It places a heavy toll on society in terms of lost job productivity and earnings, as well as cocaine-related crime. It's estimated that 482,188 emergency room visits in 2008 alone could be attributed to the drug, and it's the leading cause of heart attacks and strokes for people under 35.

The new study, though, may provide a way for people to rid themselves of the addiction. Rat brains and human brains have extremely low activity in the prefrontal cortex--a region fundamental for impulse control and decision making--when addicted to cocaine. In order to test whether altering the activity in this brain region could potentially impact addiction, the researchers employed a technique called optogenetics. This method essentially turned the activity in this region of the brain on and off by using a laser.

The researchers used light-sensitive proteins called rhodopsins and inserted them into neurons in the rat's prefrontal cortex using genetic engineering. By employing a laser tuned to the rhodopsins, the researchers could turn the nerve cells on and off.

In the end, the researchers found that by turning the cells on, compulsive behavior was wiped out in addicted rats. In contrast, switching these cells off caused non-addicted rats to become addicted. Essentially, the scientists could cure the rat of its addiction simply by using the laser.

This finding wouldn't be nearly as exciting if the researchers hadn't determined a way for it to be applicable to humans. Antonello Bonci, one of the scientists who worked on the project, stated that there is a way to stimulate a similar activation of the prelimbic cortex in people. The technique that would be used is called transcranial magnetic stimulation (TMS), which applies an external electromagnetic field to the brain. Already, the method has been used to treat symptoms of depression. The researchers plan to begin clinical trials to see if this method could help people who are addicted to cocaine and encourage them to avoid taking the drug.

The findings are published in the journal Nature.