Depth-Resolved Optical Monitoring of Neural Activity in Freely Moving Animals

Fiber photometry techniques are widely used to monitor neural activity of genetically-targeted neural populations in behaving animals. However, most implementations rely on flat-cleaved optical fibers that can only interface with shallow tissue volumes adjacent to the fiber tip due to the high scattering of brain tissue. Here we review our work on circumventing this important limitation by exploiting mode division demultiplexing using tapered optical fibers to collect photons at multiple depths simultaneously.