Adaptive optics is opening the door to super-resolution imaging within the tissues of behaving animals—with exciting implications for neuroscience and other disciplines.
“Adaptive optics will soon be an essential element for all high-resolution imaging deep in multicellular specimens,” concludes a newly published review by Na Ji.1 Formerly Group Leader at Janelia Research Campus, Howard Hughes Medical Institute (Ashburn, VA; where she worked with Nobel Laureate Eric Betzig), and now Associate Professor of Physics and Neurobiology at her PhD alma mater, University of California at Berkeley (which has also welcomed Betzig to its staff), Ji develops imaging technology for application to neurobiology—most interestingly, perhaps, in vivo brain research.
Betzig, of course, shared receipt of the 2014 Nobel Prize in chemistry for development of super-resolved fluorescence microscopy, a technique that allows subcellular imaging of biological specimens ex vivo. But putting cells on a microscope slide doesn’t allow understanding of the full context of their existence in a living organism. That’s why he and Ji, among others, are looking to enable subcellular imaging deep into the tissues of living, behaving animals.
Why adaptive optics?
The resolution of an optical system is theoretically constrained only by the diffraction of light waves. However, optical effects induced by the specimen (or the optical system itself) result in blur. Refractive index varies throughout three-dimensional (3D) tissues, decreasing both contrast and signal with increased structure complexity and depth.
As described in the 2013 book Adaptive Optics for Biological Imaging,2 adaptive optics (AO) is the most powerful and versatile approach researchers have developed to correct these aberrations. AO systems are designed to actively control and compensate for degradation and thus sharpen imagery.
Originally developed for astronomy, where it has taken more than 60…