Researchers from Istituto Italiano di Tecnologia in Lecce, Italy and Harvard Medical School created a probe designed for optogenetic applications. Optogenetics is a recently developed technique that allows scientists to selectively activate neurons within the brain, and this technology may one day be used as a therapeutic tool to treat a variety of neurological conditions. One current limitation of optogenetics is that illuminating different regions of the brain in a controlled fashion requires moving the fiber optic light source, but in practice this is nearly impossible.
The new probe uses a tapered design of an optical fiber that allows it to be used to selectively illuminate both large and small areas of the brain. This is done by controlling the nature of the light that’s sent down the fiber, compensating for what the tapered tip will do to the light.
From the study in journal Nature Neuroscience:
We use this mode to activate dorsal versus ventral striatum of individual mice and reveal different effects of each manipulation on motor behavior. Conversely, injecting light over the full numerical aperture of the fiber results in light emission from the entire taper surface, achieving broader and more efficient optogenetic activation of neurons, compared to standard flat-faced fiber stimulation. Thus, tapered fibers permit focal or broad illumination that can be precisely and dynamically matched to experimental needs.
Study in Nature Neuroscience: Dynamic illumination of spatially restricted or large brain volumes via a single tapered optical fiber…
Image and source: Istituto Italiano di Tecnologia…