Some viruses, possibly even SARS-CoV-2, can sneak into the brain through the nose. Recent studies show that microglia are ready for them when they do.

Once thought only to attack neurons, immune cells turn out to be vital for central nervous system function.

Date: July 5, 1999Table of Cell Signaling Tools At today's research pace, new signaling mechanisms within and between cells are emerging not one by one but in a chain reaction. Each new discovery has strong implications for previously established models, sometimes overturning several assumptions at once. With such a large number of interacting systems--from cell adhesion to differentiation and apoptosis--and receptor pathways, keeping up with the wealth of cell-signaling research tools can be l