The eye presents a paradox to experimental neuroscientists. On one hand, it’s accessible, its function is well understood, and its inputs can be precisely controlled, says neurobiologist William Newsome of Stanford University. “On the other hand, it is very difficult to record its electrical signals while visual behavior is actually taking place.” That’s because the hardware for electrical recordings—rigid electrodes—aren’t compatible with small, spherical, constantly moving rodent eyes.
To record retinal cell activity, researchers tend to remove the eye from the animal, dissect the retina, and lay it flat on an array of microelectrodes. While such preparations can continue to respond to light for a matter of hours, new mesh electrodes, developed by nanotechnologist Charles Lieber of Harvard University and colleagues, can remain inside a living animal’s eye, recording the same cells for several weeks.
Measuring 1.5 mm by 0.8 mm and containing 16 individual electrodes, the polymer and metal ...
