A hardware system for real-time decoding of in vivo calcium imaging data

• Published in: eLife Vol. 12
• Main Authors: Chen, Zhe, Blair, Garrett J, Guo, Changliang, Zhou, Jim, Romero-Sosa, Juan-Luis, Izquierdo, Alicia, Golshani, Peyman, Cong, Jason, Aharoni, Daniel, Blair, Hugh T
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 24.01.2023; eLife Sciences Publications Ltd; eLife Sciences Publications, Ltd
• Subjects: Accuracy; Algorithms; Animal experimentation; Animals; Behavior; Brain research; Calcium; Calcium imaging; Calcium signalling; closed-loop; Computational and Systems Biology; Computational neuroscience; Computers; Cortex (somatosensory); Data acquisition; Data collection; Datasets; Digital integrated circuits; Ethernet; Experiments; Feedback; Field programmable gate arrays; Fluorescence; Graphics software; Hippocampus; Image processing; Imaging systems; Microscopes; Microscopy; neural decoding; Neuroimaging; Neuroscience; Photons; Rats; Real time; Software; Tools and Resources; computational biology; systems biology; neural decoding; closed-loop; rat; neuroscience; calcium imaging
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.78344

Epifluorescence miniature microscopes ('miniscopes') are widely used for in vivo calcium imaging of neural population activity. Imaging data are typically collected during a behavioral task and stored for later offline analysis, but emerging techniques for online imaging can support novel closed-loop experiments in which neural population activity is decoded in real time to trigger neurostimulation or sensory feedback. To achieve short feedback latencies, online imaging systems must be optimally designed to maximize computational speed and efficiency while minimizing errors in population decoding. Here we introduce , an open-source device for real-time imaging and population decoding of in vivo calcium signals that is hardware compatible with all miniscopes that use the UCLA Data Acquisition (DAQ) interface. DeCalciOn performs online motion stabilization, neural enhancement, calcium trace extraction, and decoding of up to 1024 traces per frame at latencies of <50 ms after fluorescence photons arrive at the miniscope image sensor. We show that DeCalciOn can accurately decode the position of rats ( = 12) running on a linear track from calcium fluorescence in the hippocampal CA1 layer, and can categorically classify behaviors performed by rats ( = 2) during an instrumental task from calcium fluorescence in orbitofrontal cortex. DeCalciOn achieves high decoding accuracy at short latencies using innovations such as field-programmable gate array hardware for real-time image processing and contour-free methods to efficiently extract calcium traces from sensor images. In summary, our system offers an affordable plug-and-play solution for real-time calcium imaging experiments in behaving animals.