Measurements of neuronal activity across brain areas are important for understanding the neural correlates of cognitive and motor processes like attention, decision-making, and action selection. However, techniques that allow cellular resolution measurements are expensive and require a high degree of technical expertise, which limits their broad use. Widefield imaging of genetically encoded indicators is a high throughput, cost effective, and flexible approach to measure activity of specific cell populations with high temporal resolution and a cortex-wide field of view. Here we outline our protocol for assembling a widefield setup, a surgical preparation to image through the intact skull, and imaging neural activity chronically in behaving, transgenic mice that express a calcium indicator in specific subpopulations of cortical neurons. Further, we highlight a processing pipeline that leverages novel, cloud-based methods to analyze large-scale imaging datasets. The protocol targets labs that are seeking to build macroscopes, optimize surgical procedures for long-term chronic imaging, and/or analyze cortex-wide neuronal recordings.
@article{arxiv.2010.15191,
title = {Chronic, cortex-wide imaging of specific cell populations during behavior},
author = {Joao Couto and Simon Musall and Xiaonan R Sun and Anup Khanal and Steven Gluf and Shreya Saxena and Ian Kinsella and Taiga Abe and John P. Cunningham and Liam Paninski and Anne K Churchland},
journal= {arXiv preprint arXiv:2010.15191},
year = {2020}
}