ABOVE: Astrocytes in the mouse brain generate a fluorescent calcium indicator (gold) captured with a two-photon microscope.
ASHLEY INGIOSI, COURTESY OF CURRENT BIOLOGY
For years, researchers have assumed that the signals in the brain that make mammals sleep come from neurons and that astrocytes, glial cells that outnumber neurons five to one in the brain, were following neuronal cues. In a study published today (September 24) in Current Biology, researchers show that calcium levels—a marker of signaling activity between cells—change in astrocytes as mice sleep and wake. Without this cross-talk between astrocytes, mice don’t make up for lost sleep like they normally do, indicating that these cells in the brain have much more influence on sleep than previously thought.
“There was this idea for a long time . . . that astrocytes were just glue, pulling the brain together and are more like passive cells, but it’s not true,” says Sejal ...
