By Cédric Stefens (Imperial College, London, UK). November 6th, 2024.
The hypothesis that information processing properties emerge at this critical point has been of interest in neuroscience, inspiring a phenomenological framework for analysis of “neural avalanches” of activity that propagate with power-law distributions of size and duration. One important limitation of previous studies is the assumption of at most a single avalanche at any time. Yet, in a system as large as the brain, it is highly likely that multiple avalanches co-exist, intersecting in space or time. In this work, we investigate neural avalanches with mesoscale, single-cell resolution optical imaging, finding that as neural recording technology scales up, this assumption is no longer viable.
We recorded the activity of ~7000 layer 2/3 neurons from a 3×3 mm2 field of view (FOV) including striate and extrastriate visual cortical areas in awake, head-fixed mice, using a Diesel2p mesoscope. The mice were presented with randomised visual stimuli, and an infrared camera recorded pupil diameter. We used the seqNMF algorithm to decompose spatiotemporal patterns of neural activity into components which we found to contain individual propagating neural avalanches, for which we calculated criticality and information metrics. Avalanches detected using entire FOVs revealed a proximity to criticality in 3 recordings. seqNMF demixed 23 sets of co-occurring avalanches that displayed a range of distances to criticality, and differing information content. Pupil-related avalanches appeared to behave closer to criticality than the stimulus-related. The former tended to propagate along the antero-posterior axis, while the latter typically localised in V1 then diffused into higher visual areas. Overall, our study suggests that the interplay of co-occurring, near-critical avalanches may play an important role in information processing across cortical circuits.
Contact: Cédric Stefens, c.stefens@imperial.ac.uk
Additional authors: Cédric Stefens, Imperial College London, c.stefens@imperial.ac.uk; Hardik Rajpal,Imperial College London,h.rajpal15@imperial.ac.uk; Joseph Canzano,University of California Santa Barbara,jscanzano@ucsb.edu; Meghdad Saeedian,Imperial College London, m.saeedian@imperial.ac.uk; Mengke Yang,Imperial College London, m.yang@imperial.ac.uk; Lucilla De Arcangelis,University of Campania,lucilla.dearcangelis@unicampania.it; Henrik J Jensen,Imperial College London, h.jensen@imperial.ac.uk; Mauricio Barahona,Imperial College London,m.barahona@imperial.ac.uk; Spencer L Smith,University of California Santa Barbara,sls@ucsb.edu; Simon R Schultz,Imperial College London,s.schultz@imperial.ac.uk