The brain's polymath: Emerging roles of microglia throughout brain development

Microglia, the resident brain immune cells, have garnered a reputation as major effectors of circuit wiring due to their ability to prune synapses. Other roles of microglia in regulating neuronal circuit development have so far received compara-tively less attention. Here, we review the latest studies that have contributed to our increased understanding of how microglia regulate brain wiring beyond their role in synapse pruning. We summarize recent findings showing that microglia regulate neuronal numbers and influence neuronal connectiv-ity through a bidirectional communication between microglia and neurons, processes regulated by neuronal activity and the remodeling of the extracellular matrix. Finally, we speculate on the potential contribution of microglia to the development of functional networks and propose an integrative view of micro-glia as active elements of neural circuits.

Automated summary

In this review, the authors summarize recent studies that have expanded our understanding of microglia's role in brain wiring beyond synapse pruning. They highlight the bidirectional communication between microglia and neurons, regulated by neuronal activity and extracellular matrix remodeling, which influences neuronal numbers and connectivity. The authors also propose an integrative view of microglia as active elements in neural circuits.