Human microglia—the brain's immune cells—take years to mature, and this unusually slow development may be key to our extraordinary cognitive abilities.
The Research
Researchers at Columbia's Zuckerman Institute discovered that human microglia take about four to eight years to reach maturity, whereas in mice they mature in about three weeks. Led by Carlos Diaz-Salazar, PhD, the study was published in the journal Neuron.
The team focused on SRGAP2, a gene duplicated only in humans. Earlier work from the lab of Franck Polleux, PhD, showed that human-specific copies of this gene slow synapse maturation and increase synapse numbers in neurons. In the new study, they found SRGAP2 copies were nearly 10 times more abundant in microglia than in neurons.
Experiments with human cells and mice revealed that these gene copies dramatically slow microglia development. This suggests SRGAP2 coordinates a slow developmental pace across multiple brain cell types, a phenomenon called neoteny, which is thought to underlie human cognitive uniqueness.
Why It Matters
Microglia are not just immune cells; they help shape brain circuits by pruning synapses and fine-tuning communication. Their prolonged maturation may allow for a longer period of synaptic refinement during childhood, potentially enhancing learning and memory flexibility.
Understanding these mechanisms could offer clues about neurodevelopmental disorders, such as autism and schizophrenia, where microglial dysfunction is implicated.
What You Can Do
While you can't speed up your microglia, you can support their health with regular exercise, adequate sleep, and a diet rich in omega-3 fatty acids. These habits promote overall brain function and may aid synaptic plasticity.
Source: ScienceDaily Mind & Brain
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