The human brain is packed with star-shaped cells called astrocytes; they make up about 50 percent of cells in the cerebral cortex, and far outnumber the neurons that process and transmit information. Yet until recently, researchers thought these ubiquitous brain cells were fairly unimportant to the brain's functioning. Now a new study rebuts that theory, and indicates that astrocytes play a major role in sending blood to areas of brain activity. In the study, a team of MIT researchers peered into the visual cortex of live ferrets with an advanced microscope to watch how the brain cells responded to visual stimuli.
"Electrically, astrocytes are pretty silent," study co-author James Schummers said.... "A lot of what we know about neurons is from sticking electrodes in them. We couldn't record from astrocytes, so we ignored them." The researchers changed this perception by imaging astrocytes with two-photon microscopy. "The first thing we noticed ...
