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 Alzheimer´s disease. Microglia 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 have shown for the first time that we can track GFAP+ astrocytes and laminin+ vessels in organotypic brain slices using live-cell imaging [1]. The aim of the present study was to use microcontact printing on organotypic brain slices to label microglia with the Iba1 and CD11b antibodies and visualize them via live-cell imaging. We will show that microglia can be labelled with both antibodies and tracked with live-cell imaging for up to 20 days. Incubation in lipopolysaccharide (LPS) or granulocyte–macrophage colony-stimulating factor (GM-CSF) stimulated the migration of round amoeboid microglia, whereas interleukin-10 induced their differentiation into ramified forms. The present study shows for the first time that microglia can be easily labelled using antibodies in brain slices via microcontact printing and tracked using live-cell fluorescence microscopy for up to 20 days.