In a lab at Stanford, Doctor Karl Deisseroth is developing a kind of on and off switch, for the brain.
"We use lasers and laser light to control and to tune and modify behavior of brain cells," said Dr. Deisseroth.
First, his team added a protein that attaches to neurons in the brains of mice, making their receptors sensitive to light.
Then in a darkened room, the team uses lasers to generate different colors of light through fiber optic tubes placed in the animal's skull to stimulate the receptors. By adjusting the wave length, they're able to control how and when the neurons fire.
"We can turn them on in precise patterns. We can make them fire a second, we can make them fire their little bursts of activity 10 times a second fundamentally change the way the neuron communicates, just using pulses of laser light," said Dr. Deisseroth
Controlling the activity of neurons is already providing intriguing clues about the brain's wiring. But Dr. Deisseroth believes doctors might someday use laser light to treat psychiatric disorders like depression or even substance abuse.
One target is the dopamine neuron which controls the pleasure response.
"By using laser light delivered to the dopamine neurons, we can make animals prefer to be in one spot or another as if that spot was pleasurable to them, as if that were a pleasurable spot," Deisseroth.
Suggesting the potential of someday being able to interrupt or redirect unhealthy connections in those pathways, that play a role in drug and alcohol addiction.
"If we know a particular cell or a particular neuron needs to be tuned in just the right way, this will tell us how we need to modify these cells to treat diseases," said Deisseroth.
Dr. Deisseroth also believes the laser-light technique could someday evolve into an alternative to electronic brain stimulation -- which is currently used in extreme cases to treat diseases like Parkinson's Disease.