GLIAL CELL JUNGLE: Star-like astrocytes (red) and oligodendrocytes (green) intertwine with neurons (blue) in culture.JONATHAN COHEN, NATIONAL INSTITUTES OF HEALTH; COURTESY: NATIONAL SCIENCE FOUNDATIONBy 1899, nearly 50 years after glia were discovered, Spanish neuroscientist Santiago Ramón y Cajal recognized that research on these cells was lagging behind studies on their flashier neuronal cousins. “What functional significance may we attribute to the neuroglia?” he wrote in his multivolume book Texture of the Nervous System of Man and the Vertebrates. “Unfortunately, in the present state of science it is not possible to answer this important question except through more or less rational conjectures. In the face of this problem, the physiologist is totally disarmed for lack of methods.”
Despite making up 50 to 80 percent of the cells of the human brain (estimates vary), glial cells were thought to simply provide structural integrity to the brain and to nourish and mop up after neurons. And it would be the better part of a century before Ramón y Cajal’s call for more methods to study glia was answered.
“Glia were not a major point of interest in neuroscience,” says Marc Freeman, an investigator with the Howard Hughes Medical Institute (HHMI) who studies fruit fly glia at the University of Massachusetts Medical School. “Neurons were the ones that fired signals. . . . Glial cells, when you plug them in, don’t do a whole lot.”
“People are saying neurons are overstudied, and glia are understudied.”—Ben ...