Lasers that switch cocaine addiction on and off
Researchers are exploring how laser light can be used on the brain to inhibit addictive behavior -- in particular, how you can turn "on and off" cocaine addiction in rats.
Scientists at the National Institutes of Health (NIH) and the Ernest Gallo Clinic and Research Center at UC San Francisco (UCSF) have discovered that by stimulating particular areas of the brain with light, addictive behavior can be removed in rats -- or used to encourage addiction to substances like cocaine.
By shining a laser light in the prelimbic region of the prefrontal cortex, the researchers say the compulsion to ingest cocaine was gone.
This particular area of the brain is associated with impulses and decision making, and studies have shown that both humans and rats with low activity ratings in the prefrontal cortex tend to be more at risk of becoming compulsively addicted to cocaine.
The scientists used genetic engineering to insert light-sensitive proteins into a rat's prefrontal cortex. The team then activated this region using lasers, which turned the nerve cells on and off. Turning on the cells removed compulsive behavior, whereas switching them off turned non-addicted rats into addicts.
The study shows that new types of therapy may inhibit the same behavior in humans. Trials are already being designed, and it is hoped that by using electromagnetic stimulation outside the scalp rather than lasers on the scalp, the same results may appear.
The research has been described this week in the journal Nature. It is estimated that 1.4 million Americans are addicted to cocaine, and cocaine abuse is a main cause of heart attacks and strokes in people under 35 years of age.
Image credit: B.Chen/NIDA