Axon Initial Segment–Associated Microglia

摘要: Microglia are the brain's resident immune cells and function as main defense against pathogens or injury. However, in absence of disease, microglia have other functions normal brain. For example, previous studies showed that contribute to circuit refinement synaptic plasticity developing adult brain, respectively. Thus, actively participate regulating neuronal excitability function. Here, we report cortex, but not brain regions, a subset extend single process specifically associates overlaps with axon initial segment (AIS), site where action potentials generated. Similar associations were observed dendrites distal axons. Microglia–AIS interactions appear early development, persist throughout adulthood, conserved across species including mice, rats, primates. these lost after microglial activation following injury, suggesting such may be part healthy Loss CX3CR1 receptors, specialized extracellular matrix surrounding AIS, did disrupt interaction. loss AIS proteins by neuron-specific deletion master scaffold AnkyrinG disrupted microglia–AIS interactions. These results reveal unique population interact cortex.