RT Journal Article SR Electronic T1 Multipoint and large volume fiber photometry with a single tapered optical fiber implant JF bioRxiv FD Cold Spring Harbor Laboratory SP 455766 DO 10.1101/455766 A1 Pisano, Filippo A1 Pisanello, Marco A1 Maglie, Emanuela A1 Balena, Antonio A1 Sileo, Leonardo A1 Spagnolo, Barbara A1 Hyun, Minsuk A1 De Vittorio, Massimo A1 Sabatini, Bernardo L. A1 Pisanello, Ferruccio YR 2018 UL http://biorxiv.org/content/early/2018/10/29/455766.abstract AB Techniques to monitor functional fluorescence signal from the brain are increasingly popular in the neuroscience community. However, most implementations are based on flat cleaved optical fibers (FFs) that can only interface with shallow tissue volumes adjacent to the fiber opening. To circumvent this limitation, we exploit modal properties of tapered optical fibers (TFs) to structure light collection over the wide optically active area of the fiber taper, providing an approach to efficiently and selectively collect light from the region(s) of interest. While being less invasive than FFs, TF probes can uniformly collect light over up to 2 mm of tissue and allow for multisite photometry along the taper. Furthermore, by micro-structuring the non-planar surface of the fiber taper, collection volumes from TFs can also be engineered arbitrarily in both shape and size. Owing to the abilities offered by these probes, we envision that TFs can set a novel, powerful paradigm in optically targeting not only the deep brain, but, more in general, any biological system or organ where light collection from the deep tissues is beneficial but challenging because of tissue scattering and absorption.