Microglial confetti party

Abstract

Microglia are highly heterogeneous and plastic. However, the dynamics of their turnover have been difficult to visualize. A new multicolor reporter system reveals a plastic but stable network of microglia during health and disease.

Figure 1

Microglial network regulation in health and disease. (a) The Confetti reporter strain crossed with a myeloid-cell-specific Cre line generates the Microfetti mouse. It allows random multicolor labeling of microglia with one of four fluorescent proteins: nuclear green fluorescent protein (nGFP), cytoplasmic yellow fluorescent protein (YFP), cytoplasmic red fluorescent protein (RFP) and membrane-localized cyan fluorescent protein (mCFP). (b) This model reveals random local self-renewal of microglia in steady-state conditions. Local damage induces microgliosis through clonal expansion at the site of the lesion, which resolves by egress (red arrow) and apoptosis (gray cell) of excess cells to restore the resting microglia network.