Microglia Found to Play Regulatory Role with Developing Neurons

Microglia are established as essential immune cells for the brain, reducing inflammation and responding to any damage within the cerebral microenvironment. Microglia’s role in neurodevelopmental disorders has recently been of increasing interest to researchers, but the exact dynamic mechanisms of action remain unknown. That’s why a team at the Laboratory of Neuroimmunology of the Institute of Experimental Medicine, Budapest (IEM), Hungary, investigated how microglia directly interact with developing neurons.

The team of researchers, led by researcher Ádám Dénes, investigated microglia’s role in physiological and pathological conditions by using high-resolution molecular anatomy techniques combined with light and electron microscopy, as well as ex vivo imaging studies. The team identified a novel form of direct cell communication between neurons and microglia, named “somatic microglia-neuron junctions.” They found that these contact sites play a unique role in assisting injured neurons. 

The researchers’ multifaceted experimental approach allowed them to look at the direct connections between microglial and developing neurons during embryonic development and after birth. “The special, dynamically changing anatomical connections between microglia and developing, immature neurons are similar to the previously discovered somatic microglial junctions in many ways, and their special molecular composition and ultrastructure enable microglia to continuously monitor and effectively influence the development and integration of neurons into complex networks,” says first author Csaba Cserép.

Normal cerebral cortex development was inhibited when the team inhibited communication through enriched microglial receptors. They inferred that microglia must play a role in healthy neuronal development, particularly in regulating development through these particular interaction sites.

“More thorough understanding of microglial mechanisms that are required for the proper development of the brain may help to find novel therapies for neurodevelopmental disorders and other forms of brain diseases that represent an unresolved challenge worldwide,” says Ádám Dénes, the publication’s last author.

Their findings, published in the journal Cell Reports, may have far-reaching implications on neurodevelopmental interventions and therapies. Future work can examine these sites in more detail to contribute to more effective diagnosis and treatment of neurological disease.