Where microglial cells come from and how they renew in amyloid plaques of Alzheimer’s model mice

The number of microglial cells in plaques increases from 1 or 2 in early plaques to more than 100 in older plaques.

• Microglial cells are found in fibrillar plaques in the brains of Alzheimer's disease patients and transgenic mice.
• Cored plaques primarily develop in perivascular regions, indicating a link between blood vessels and plaque formation.
• Plaques appear to be formed by inflammatory cells that originate from the blood.
• An increase in microglial cells is associated with growth of amyloid cores and neuronal degeneration.
• A notable turnover of inflammatory cells occurs in larger plaques, particularly at the boundary with blood vessels.

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