Stable behavioral state-specific mesoscale activity patterns in the developing cortex of neonates

Abstract

Endogenous neuronal activity is a hallmark of the developing brain. In rodents a handful of such activities were described in different cortical areas but the unifying macroscopic perspective is still lacking. Here we combined large-scale in vivo Ca2+ imaging of the dorsal cortex in naturally behaving neonatal mice with advanced mathematical analyses to reveal unique behavioral state-specific maps of endogenous activity. These maps were remarkably stable over time within and across experiments, and used patches of correlated activity with little hemispheric symmetry as well as stationary and propagating waves as building blocks. Importantly, the maps recorded during motion and rest were almost inverse, with sensory-motor areas active during motion and posterior-lateral areas active at rest. The retrosplenial cortex engaged in both resting- and motion-related activities, building functional long-range connections with respective cortical areas. Together, these data provide so far the most complete view on the endogenous network activity pacing development of cortex-wide functional networks in neonates.