Neurons turned on and off using ultrasound

New York Times : Optogenetics, a technique that uses light to activate or deactive genetically modified brain cells, was developed by researchers to study how brains function. However, the technique requires the insertion of a fiber-optic cable into the brain. Now Sreekanth H. Chalasani of the Salk Institute in San Diego, California, and his colleagues have demonstrated a similar, noninvasive technique that uses ultrasound, which they have dubbed sonogenetics. The test was performed on Caenorhabditis elegens, a microscopic worm. Although lacking a developed brain, the worm does have neurons that are very similar to those in more advanced animals. If the technique works on more complex animals, it would be a noninvasive way to study complex brains and neural systems. C. elegens is so well studied that scientists have a complete map of the connections between the animal’s 302 neurons. Chalasani’s team found a mechanism that made the worm’s neurons sensitive to ultrasound. The researchers then chose and genetically modified an individual neuron so that they could turn it on and off.