Microprisms enable enhanced throughput and resolution for longitudinal tracking of neuronal ensembles in deep brain structures

Abstract

Microprism-mediated calcium imaging of deep brain structures allows for reliable tracking of thousands of cells across days, a marked improvement compared with industry-standard approaches utilizing gradient-index (GRIN) lenses. We aim to develop a method to record, track, and functionally characterize thousands of cortical and subcortical neurons using an endoscopic microprism and to benchmark the performance against traditional GRIN lenses. To improve the visualization throughput of subcortical ensembles, we developed and characterized a protocol to implant a microprism. We performed two-photon calcium imaging through microprisms and compared the yield, cell quality, and optical characteristics to industry-standard GRIN lenses. We found that our microprism method can stably isolate and track thousands of active neurons across days to weeks. This high-throughput calcium imaging approach facilitates longitudinal functional characterization of large groups of neural ensembles in vivo in cortical and subcortical brain structures. This method produces high fidelity trackable cells with superior resolution quality and higher spatial precision when compared with industry-standard GRIN lenses. The microprism technique represents a significant improvement in throughput and resolution to functionally characterize neuronal ensemble dynamics within deep brain tissues.