Single Worm Neurons Remotely Controlled with Lasers: Scientific American

Single Worm Neurons Remotely Controlled with Lasers: Scientific American: Leifer and his collaborators genetically engineered the one-millimeter-long nematode worm to make particular cells in its body sensitive to light, a technique called optogenetics, developed in recent years by Stanford University psychiatrist and bioengineer Karl Deisseroth [see Deisseroth's "Controlling the Brain with Light," Scientific American, November 2010]. Because the worm's body is transparent, sharply focused lasers, pointed with an accuracy of 30 microns, could turn on or suppress individual neurons with no need for electrodes or other invasive methods...
Other teams have performed optogenetic studies and controlled individual neurons on immobilized worms. But, to understand the organism's physiology, says Leifer, it is necessary to manipulate it as it swims freely.