Live-Cell Imaging of Microglia in Organotypic Brain Slices Using Microcontact Printing.

Microglia are brain immune cells that phagocytose cell debris and beta-amyloid plaques in patients with Alzheimer's disease. They develop from round amoeboid cells into ramified microglia or large macrophages, which can be studied in three-dimensional organotypic mouse brain slices. In a recent publication, we showed for the first time that we can track GFAP+ astrocytes and laminin+ vessels in organotypic brain slices using live-cell imaging . The aim of the present study was to use microcontact printing on organotypic brain slices to label microglia with Iba1 and CD11b antibodies and visualise them through live-cell imaging. We show that microglia can be easily labelled with antibodies and tracked via live-cell fluorescence microscopy for up to 20 days. Incubation in lipopolysaccharide (LPS) or granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates the migration of round amoeboid microglia, whereas interleukin-10 induces their differentiation into ramified forms. Taken together, we show the first-time live cell imaging of microglia in organotypic mouse brain slices using microcontact printing.