The Spaces Between
Cells get all the glory, but the spaces surrounding them are important, too.
What’s in a brain? Neurons, chemical messengers, electric signals—and a lot of empty space. The space between cells takes up a fifth of the volume inside our brains.
And although all our thoughts and mental functions traffic through this vital region, scientists are just beginning to unlock its secrets.
Neurobiologists Charles Nicholson of
By injecting tracers and tracking their diffusion through the living brains of rats and other animals, they have discovered that about 20 percent is extra cellular space, filled with cerebrospinal fluid—the same liquid that surrounds and cushions the brain and spinal cord.