STANFORD, Calif., April 5 (UPI) -- U.S. neuroscientists have used light to control the activity of brain cells, thereby inhibiting neural activity on a millisecond timescale.
Dr. Karl Deisseroth and his Stanford University colleagues introduced NpHR -- a light-driven chloride pump that occurs naturally in microorganisms known as archaea -- into cultured mammalian neurons and brain tissue in the laboratory.
The researchers discovered training light pulses onto those cells inhibited neural activity.
By simultaneously expressing both membrane proteins in the muscle cells or motor neurons of the nematode worm Caenorhabditis elegans, the researchers were able to control the worm's locomotive behavior; the worms stopped and started muscle contractions when yellow and blue lights were shone on them.
Deisseroth said the findings demonstrate light-responsive proteins can be used simultaneously to permit fast, bidirectional and reversible control over living neural circuits. They can also be used with calcium imaging techniques to provide a powerful tool for studying and manipulating brain activity with high precision.
The study appears in the journal Nature.