Spontaneous neural fluctuations and traveling waves are coordinated topographically across cortical and subcortical areas

Spontaneous neural fluctuations and traveling waves are often observed in large scale population activity in diverse brain areas and in various brain states (Lubenov et al. 2009; Muller et al. 2016; Hamid et al. 2021). Spatiotemporal dynamics of neural activity, including traveling waves, likely implement diverse computations, including motor planning, decision making, and memory consolidation (Ermentrout & Kleinfeld 2001; Muller et al 2018). However, the detailed spatiotemporal patterns of wave propagation have not been well characterized in awake mammals. Critically, it is still largely unknown whether spatiotemporal patterns are shared and coordinated across different brain areas. Using GCaMP7f widefield imaging in the mouse dorsal cortex, we identified that 3-6 Hz oscillations during awake immobility (Einstein et al. 2017; Jacobs et al. 2022; Nestvogel & McCormick 2022) are globally distributed. Traveling waves, including spirals, emerged during 3-6 Hz oscillations. Spiral waves are highly concentrated in the center of the somatosensory cortex (SSp), and coordinated between left and right hemispheres, as well as between anterior and posterior cortex. As a result of observing this spatial phase symmetry, we found that neural fluctuations and spiral waves in the posterior cortex can be fully predicted by anterior cortical fluctuations with linear regression, and the spatial distribution of the activity regression kernels closely matches the axonal projection maps. To determine whether these waves are coordinated beyond the cortex, we used simultaneous cortical widefield imaging and 4-shank Neuropixels 2.0 recording in the subcortical areas. We quantified moment-to-moment cortical wave with optical flow methods and found that the timing, location and propagation direction of the cortical wave could be predicted using rich subcortical spiking data from striatum and thalamus. Together these results demonstrate that the propagating waves of neural activity are shared across multiple cortical maps and subcortical regions, raising new possibilities for their functional consequences.