New ripples rock optogenetics, IR microscopy

Karen A. Newman

The circle of life in scientific research could perhaps be illustrated by the spreading ripple created by dropping a stone in a lake, the next ring wider than the one before. The rock – the discovery – lives on in its technological progeny, enabling researchers to widen their investigations, dropping new rocks, making new waves. Such is certainly the case with the nascent science of optogenetics, which is bringing new insight into information processing in the brain and perhaps offering hope for sufferers of Parkinson’s and related diseases.

In our cover story, “Optogenetics: A conversation with Ed Boyden,” contributing editor Gary Boas tells us that Boyden, now head of MIT’s Synthetic Neurobiology Group, was collaborating with Stanford University’s Karl Deisseroth in 2004 when Deisseroth’s team discovered the effect of channelrhodopsin-2 on mammalian neurons. The ripples from that discovery are still spreading, as Boyden’s group at MIT is working to develop new hardware that “better facilitates optical silencing or driving of neural activity in complexly shaped brain circuits,” Boas writes.

At a meeting in March, Boyden’s team “presented a suite of hardware technologies capable of multiscale optical neural control.” It included “an array of LED-coupled 200-µm optical fibers allowing delivery to tens of sites in the brain of a mouse; a modular fluidic cooling system, enabling operation for very long periods of time; and 10 LEDs for 30 continuous seconds or three LEDs indefinitely.” Boas reports that “the arrays and cooling systems are light enough to be kept to the head of a freely moving mouse.”

You can find Boas’ article beginning on page 20 and anticipate along with the rest of us the next ring of knowledge to spread from that single dropped stone.

Another ripple is forming around a concept for IR microscopy, introduced by author John Coates, based on a broadly tunable IR quantum cascade laser. The improved spectral radiance of the laser provides more efficient optical coupling to smaller sampling areas, according to the author, which can translate to more efficient spectrally specific IR imaging. The new technology expands IR microscopy into new application areas, including bioscience research and medical diagnostics. His article, “Next-generation IR microscopy: The devil is in the detail,” begins on page 24.

Also in this issue, author Marie Cherrier describes both a direct imaging setup and a Shack-Hartmann wavefront sensor-based measurement system used in testing the complex intraocular lenses that replace human eye crystalline lenses in cataract patients. Her article, “Characterization of intraocular lenses: Different measurement methods,” begins on page 34.

BioPhotonics editors will be on the scene covering all the latest dropped rocks and spreading waves featured at Neuroscience 2010, Nov. 13-17 in San Diego, and the American Society for Cell Biology 50th Annual Meeting, Dec. 11-15 in Philadelphia. I hope you’ll take a moment to say hello if you see them at either event. And you can contact me at any time via e-mail at karen.newman@photonics.com.