Spatially Selective Holographic Photoactivation and Functional Fluorescence Imaging in Freely Behaving Mice with a Fiberscope

Correlating patterned neuronal activity to defined animal behaviors is a core goal in neuroscience. Optogenetics is one large step toward achieving this goal, yet optical methods to control neural activity in behaving rodents have so far been limited to perturbing all light-sensitive neurons in a large volume. Here we demonstrate an all-optical method for precise spatial control and recording of neuronal activity in anesthetized and awake freely behaving mice. Photoactivation patterns targeted to multiple neuronal somata, produced with computer-generated holography, were transmitted to the mouse brain using a micro-objective-coupled fiber bundle. Fluorescence imaging through the same device, via epifluorescence, structured illumination, or scanless multipoint confocal microscopy, allowed imaging of neurons and recording of neuronal activity. The fiberscope was tested in mice coexpressing ChR2-tdTomato and GCaMP5-G in cerebellar interneurons, delivering near-cellular resolution photoactivation in freely behaving mice.