ABSTRACTBehavior results in widespread activation of the cerebral cortex. To fully understanding the cerebral cortex’s role in behavior therefore requires a mesoscopic level description of the cortical regions engaged and their functional interactions. Mesoscopic imaging of Ca2+ fluorescence through transparent polymer skulls implanted on transgenic Thy1-GCaMP6f mice reveals widespread activation of the cerebral cortex during locomotion, including not just primary motor and somatosensory regions but also premotor, auditory, retrosplenial, and visual cortices. To understand these patterns of activation, we used spatial Independent Component Analysis (sICA) that segmented the dorsal cortex of individual mice into 20-22 Independent Components (ICs). The resulting ICs are highly consistent across imaging sessions and animals. Using the time series of Ca2+ fluorescence in each IC, we examined the changes in functional connectivity from rest to locomotion. Compared to rest, functional connectivity increases prior to and at the onset of locomotion. During continued walking, a global decrease in functional connectivity develops compared to rest that uncovers a distinct, sparser network in which ICs in secondary motor areas increase their correlations with more posterior ICs in somatosensory, motor, visual, and retrosplenial cortices. Eigenvector centrality analysis demonstrates that ICs located in premotor areas increase their influence on the network during locomotion while ICs in other regions, including somatosensory and primary motor, decrease in importance. We observed sequential changes in functional connectivity across transitions between rest and locomotion, with premotor areas playing an important role in coordination of computations across cortical brain regions.SIGNIFICANCEBehavior such as locomotion requires the coordination of multiple cerebral cortical regions to accurately navigate the external environment. However, it is unclear how computations from various regions are integrated to produce a single, coherent behavioral output. Here, wide-field, epifluorescence Ca2+ imaging across the dorsal cerebral cortex reveals the changing functional interactions among cortical regions during the transition from rest to locomotion. While functional connectivity among most cortical nodes primarily decreases from rest to locomotion, a well-defined network of increased correlations emerges between premotor and other cortical regions with an increase in the importance of the premotor cortex to the network. The results suggest that the role of the premotor areas in locomotion involves coordinating interactions among different cortical regions.
Brain functional connectivity modulates social bonding in monogamous voles
