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bioRxiv · 10.1101/116350

Deep brain fluorescence imaging with minimally invasive ultra-thin optical fibers

Ohayon, S.·Caravaca Aguirre, A. M.·Piestun, R.·DiCarlo, J. J.
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Abstract

A major open challenge in neuroscience is the ability to measure and perturb neural activity in vivo from well-defined neural sub-populations at cellular resolution anywhere in the brain. However, limitations posed by scattering and absorption prohibit non-invasive (surface) multiphoton approaches1,2 for deep (>2mm) structures, while Gradient Refreactive Index (GRIN) endoscopes2-4 are thick and cause significant damage upon insertion. Here, we demonstrate a novel microendoscope to image neural activity at arbitrary depths via an ultrathin multimode optical fiber (MMF) probe that is 5-10X thinner than commercially available microendoscopes. We demonstrate micron-scale resolution, multispectral and volumetric imaging. In contrast to previous approaches1,5-8 we show that this method has an improved acquisition speed that is sufficient to capture rapid neuronal dynamics in-vivo in rodents expressing a genetically encoded calcium indicator. Our results emphasize the potential of this technology in neuroscience applications and open up possibilities for cellular resolution imaging in previously unreachable brain regions.

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Ohayon, S., Caravaca Aguirre, A. M., Piestun, R., DiCarlo, J. J.. 2017-03-13. Deep brain fluorescence imaging with minimally invasive ultra-thin optical fibers. https://doi.org/10.1101/116350

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