FLICKR, STEVE JURVETSONUsing a modified scorpion neurotoxin or antibodies to target gold nanoparticles to the surface of neurons, researchers have created a new way to stimulate brain cells in culture. All it takes is a little bit of light to heat the particles, which changes the capacitance of the membrane, resulting in the depolarization of the cell and the firing of an action potential.
“We call it optogenetics without the genetics,” said biophysicist Francisco “Pancho” Bezanilla of the University of Chicago, “exciting cells in the nervous system without going through all the difficulty of creating a transgenic animal. . . . It’s a shortcut.”
Bezanilla launched the project after chatting with vision neuroscientist David Pepperberg of the University of Illinois at Chicago at a conference a few years back focused on solutions to restore vision in patients suffering from macular degeneration, in which the photoreceptors have degenerated but the ganglion cells that communicate with the brain are often still intact and functional. Bezanilla’s group had previously shown that heat can be used to excite neurons by producing a rapid change in the electrical charge across the cell membrane, activating ...
