Crossing the scales: Opto-magnetic imaging can reveal cortical propagation of circuit-dominating slow wave events

Motivation: Slow wave events (SWEs) or population up states occur in the mammalian cortex mainly during sleep or under anesthesia. Disrupted SWE propagation activity may be implicated in early-stage neurological disorders Goal(s): Following the slow wave event (SWE) as a distinct neurophysiological event across the scales in rodents. Approach: We explore the neuronal recruitment and propagation of SWE from single neurons to the cortex, intertwining optical and translationally relevant fMRI. Results: All active cells of the local microcircuit participate in a population wide SWE. Implementing an optomagnetic integration concept (OPTOMAIC), we could measure cortical propagation velocities of neurophysiologically-defined SWEs by non-invasive fast fMRI. Impact: This study bridges concepts and methods spanning from optical imaging of local microcircuits to optic-fiber photometry and fast fMRI to follow a defined neurophysiological event, the slow wave event, across the scales, from single cells to non-invasive cortex wide fMRI.