From tomorrow's New York Times:
The Beam of Light That Flips a Switch That Turns on the Brain
By INGFEI CHEN
Published: August 14, 2007
One of the newest, fastest strategies co-opts a photosensitive protein called channelrhodopsin-2 from pond scum to allow precise laser control of the altered cells on a millisecond timescale. That speed mimics the natural electrical chatterings of the brain, said Dr. Karl Deisseroth, an assistant professor of bioengineering at Stanford.
“We can start to sort of speak the language of the brain using optical excitation,” Dr. Deisseroth said. The brain’s functions “arise from the orchestrated participation of all the different cell types, like in a symphony,” he said.
Laser stimulation can serve as a musical conductor, manipulating the various kinds of neurons in the brain to reveal which important roles they play.
This light-switch technology promises to accelerate scientists’ efforts in mapping which clusters of the brain’s 100 billion neurons warble to each other when a person, for example, recalls a memory or learns a skill. That quest is one of the greatest challenges facing neuroscience.
The channelrhodopsin switch is “really going to blow the lid off the whole analysis of brain function,” said George Augustine, a neurobiologist at Duke University in Durham, N.C.
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