The Other Brain Cells: New Roles for Glia

Neurons have always been the stars of brain research, but scientists are now realizing that nonneuronal cells known as glia—which make up around 90 percent of cells in the brain—are not the mild-mannered understudies they appeared to be. Some glia may even fire electrical signals, a finding that overturns a central dogma of neuroscience that holds that neurons are the only cells in the brain with such signaling ability.


Last winter, when neuroscientists at University College London examined glia known as oligodendrocyte precursor cells (OPCs), they were astounded to find that, just like neurons, one subtype fired electrical signals in response to electrical stimulation. Before this study little was known about the function of OPCs, says study leader Ragnhildur Karadottir, except that they could develop into new oligodendrocytes, a type of glial cell that forms an insulating sheath around neurons like the rubber on an electrical cord.