For many years, most neuroscientists thought about development through the lens of genes, cell lineages and cell fates. This was indeed the case when I first encountered the study by Bonifazi et al., just as I was beginning my PhD. This paper expanded that view in a way that stayed with me.

It suggested that brain development is not only about assembling the right combination of cell types, but also about how activity is organized in time. In particular, it revealed that early network dynamics are not simply emergent but can be orchestrated by a small number of inhibitory hub neurons, which positions activity itself as a key driver of circuit formation.