Mechanism of synapse elimination by microglia

Microglia engulf synaptic material in a process named microglial pruning indicating its active role in sculpting brain circuits by a process of phagocytosis. But, how microglial synapse elimination occurs is not clear yet.

The researchers propose two mechanisms for synaptic elimination, culling and scavenging. Microglia during culling uses a contractile ring to sever the neuronal plasma membrane, removing the unwanted synapse. Synapse elimination during scavenging is neuronal-driven, and the neuronal plasma membrane fission machinery sheds off synapses that are later phagocytosed by microglia. 

The authors discuss the limitations of both the mechanisms and evaluate therapeutic value of phagocytosis modulators.

https://www.nature.com/articles/s41593-024-01818-w

https://sciencemission.com/Synaptic-connectome-of-the-Drosophila-circadian-clock