Abstract
The developing neocortex exhibits patterned spontaneous network activity with various synchrony levels. However, the role of such activity in the formation of cortical circuits remains unclear. We previously reported that the development of callosal axon projections, one of the major long-range axonal projections in the brain, is activity dependent. Here, using a genetic method to manipulate network activity in a stage-specific manner, we demonstrated that spontaneous cortical network activity contributes to the region- and lamina-specific projections of callosal axons in the mouse visual cortex and that this process has a “critical period”: restoring neuronal activity during that period resumed the projections, whereas restoration after the period failed. Furthermore, in vivo imaging revealed that less correlated network activity was critical. Together, our findings suggest that a distinct pattern of spontaneous network activity in a specific developmental stage underlies the formation of long-range axonal projections in the developing neocortex.
Competing Interest Statement
The authors have declared no competing interest.