http://www.eurekalert.org/pub_releases/2015-09/si-ifs091015.php
In optogenetics, a light sensitive switch is added to a neuron. When that switch is triggered, the neuron responds. Here researchers have done something similar this time with sound. An ultrasound triggered responses in neurons with sound sensitive switches. This technique could be much less invasive then implanting a fiber optic cable to pulse light onto specific neurons.