Abstract
AbstractFiber photometry is a technique of growing popularity in neuroscientific research. It is widely used to infer brain activity by recording calcium dynamics in genetically defined populations of neurons. Aside from the wide variety of calcium indicators, other genetically encoded biosensors have recently been engineered to measure membrane potential, neurotransmitter release, pH, or various cellular metabolites, such as ATP or cAMP. Due to the spectral characteristics of these molecular tools, different assemblies of optical hardware are usually needed to reveal the full potential of different biosensors. In addition, the combination of multiple biosensors in one experiment often requires the investment in more complex equipment, which limits the flexibility of the experimental design. Such constraints often hamper a straightforward implementation of new molecular tools, evaluation of their performance in vivo, and design of new experimental paradigms - especially if the financial budget is a limiting factor. Here, we propose a novel approach for fiber photometry recordings, based on a multimode optical fused-fiber coupler (FFC) for both light delivery and collection. Recordings can readily be combined with optogenetic manipulations in a single device without the requirement for dichroic beam-splitters. In combination with a multi-color light source and appropriate emission filters, our approach offers remarkable flexibility in experimental design and facilitates the implication of new molecular tools in vivo at minimal cost. The ease of assembly, operation, characterization, and customization of this platform holds the potential to foster the development of experimental strategies for multicolor fused fiber photometry (FFP) combined with optogenetics far beyond its current state.Abstract FigureHighlightsFused Fiber Photometry (FFP) enables straightforward monitoring and manipulation of brain activityFFP allows monitoring of indicators with virtually any spectral characteristicsFFP is compatible with simultaneous optogenetic manipulationEasy assembly, characterization, and customization
Publisher
Cold Spring Harbor Laboratory