In 2004, Stanford neuroscientist Karl Deisseroth pioneered research into a new way to treat addiction. Optogenetics, a treatment using light to stimulate neurons in the brain, has been used to study drug addiction, anxiety, Parkinson’s disease, depression, and autism.

In 2013 researchers found that stimulating one region of the brain with light appeared to reduce lab rats’ compulsion to seek cocaine. Optogenetics currently being used to study cocaine addiction, but the research is still considered to be in its infancy.

What is Optogenetics?

Optogenetics is a new way to see brain activity using basic science. The science uses a gene found in green algae. The gene itself helps algae create the right light level in ponds to photosynthesize. Injecting the gene to specific brain cells, such as brain cells that carry dopamine and serotonin, allows scientists to watch animal behaviors. This helps them to discover how stimulating certain parts of the brain can affect behavior patterns.

This helps deepens our understanding of the human brain and how cells can be altered or modified by other factors, such as drug or alcohol use.

Understanding How Optogenetics Can Help

A 2016 study created by neuroscientists from the University of Oxford used light to alter mice’s memories so that they no longer associated specific locations where they once “used” cocaine with the drug. This groundbreaking study suggested that by interfering with the brain’s “memory” of places it once associated with pleasure.


In this study, researchers injected the mice with a chemical that caused the neurons to produce a light-sensitive protein when the mouse was in the cocaine-associated area.

Out of all the brain, 133 neurons that lit up and implanted light-transmitting fibers near the neurons in the mice’s brains when the mice were “using” cocaine. Presumably, the mice were addicted – and other studies have shown that caged mice will go to the site of cocaine – and self-administer drugs when given a chance. This is considered to be the crux of addiction when it comes to animal life – animals don’t know what “using” is, but they are quickly addicted to drugs.

Once the mice are acclimated to “using” the cocaine, they will return time and time again to the site they first found it. But when researchers used light to turn off those spatial mapping neurons in the hippocampus, the mice no longer returned to the cocaine-associated area. Study authors believe the mice’s memories were altered to forget the drug-related association.

Researchers believe that this means that future studies could use optogenetics to help retrain the brain to halt addictive behavior.

Karl Deisseroth, the scientist who discovered optogenetics, has now won the prestigious Kyoto Prize, Japan’s highest private honor, for pioneering the technique known as optogenetics. For years to come, scientists hope to use it to better understand links between brain activity and behavior.