Person:

Datta, Sandeep

Improvements in imaging technology and the development of powerful machine learning algorithms are revolutionizing the study of animal behavior in the laboratory. These innovations promise to reveal both global and local features of action relevant to understanding how the brain functions. A study in BMC Biology describes one such tool called OptiMouse, which is an open source platform that uses video to capture key features of mouse behavior, including information relevant to olfactory investigation. See research article: 10.1186/s12915-017-0377-3

Optogenetics promises spatiotemporal precise control of neural processes using light. However, the spatial extent of illumination within the brain is difficult to control and cannot be adjusted using standard fiber optics. We demonstrate that optical fibers with tapered tips can be used to illuminate either spatially restricted or large brain volumes. Remotely adjusting the light input angle to the fiber varies the light-emitting portion of the taper over several millimeters without movement of the implant. 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 when compared to the standard flat-faced fiber stimulation. Thus, tapered fibers permit focal or broad illumination that can be precisely and dynamically matched to experimental needs.