Researchers here report on a compelling demonstration that shows the degree to which dysfunctional microglia contribute to age-related neurodegeneration. The scientists use a pharmacological approach to greatly deplete the microglial population and then allow it to recover naturally. The influx of new microglia improves many aspects of brain function, though interestingly this procedure doesn’t appear to affect the inflammatory status of brain tissue. Most neurodegenerative conditions are thought to be driven to some degree by inflammation, while the data here suggests that the activities of glial cells that support neuronal function are not to be neglected.
The data also suggests that inflammation is a reaction to the state of brain tissue, rather than something that arises from intrinsic issues within glial cells. That conclusion is contradicted by other recent research in which senescent glial cells are shown to definitively contribute to the pathology of neurodegenerative disease. Perhaps the resolution of this contradiction is that senescent glial cells are resistant to depletion via the methodology used here, but that is pure speculation on my part.
Microglia are the primary immune cells of the central nervous system (CNS), where they act as responders in the event of infection or