ORACA – an open-source software for Online Real-time neural Activity extraction and offline Cross-session Analysis
AbstractThe idea to combine in vivo functional imaging with optogenetic stimulation to achieve closed-loop, all-optical recording and manipulation of neurons and neural circuits is appealing yet challenging. Other than necessary hardwares, it requires an analysis software fast enough to extract neural activities from imaging data in real time. Here we present an open-source, integrative image processing toolbox ORACA (Online Real-time Activity extraction and offline Cross-session Analysis), which provides solutions for both fast online and accurate offline data analyses. We developed fast GPU-based algorithms that can finish raw image registration, automatic identification and activity extraction of neurons within seconds after image acquisition. Offline analysis pipeline features a new cross-session alignment algorithm that takes into account the angle differences across imaging sessions, useful for shared microscope or long imaging intervals. A modular, user-friendly software that can be used as a complete package or independent modules, ORACA can effectively facilitate the image analysis process, especially for all-optical closed-loop control and long-term repeated imaging.