TY - JOUR T1 - Dynamically controlled light delivery over large brain volumes through tapered optical fibers JF - bioRxiv DO - 10.1101/094524 SP - 094524 AU - Ferruccio Pisanello AU - Gil Mandelbaum AU - Marco Pisanello AU - Ian A. Oldenburg AU - Leonardo Sileo AU - Jeffrey E. Markowitz AU - Ralph E. Peterson AU - Andrea Della Patria AU - Trevor M. Haynes AU - Mohamed S. Emara AU - Barbara Spagnolo AU - Sandeep R. Datta AU - Bernardo L. Sabatini AU - Massimo De Vittorio Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/12/15/094524.abstract N2 - 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 large brain volumes or dynamically selectable subregions. 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. ER -