Glial Cells Run Support

Glial cells are at least as numerous as neurons and do far more than hold things in place. Oligodendrocytes wrap axons in myelin insulation, boosting signal speed dramatically — multiple sclerosis destroys this myelin, which shows how vital it is.

Astrocytes also help process information, tuning how signals cross synapses and forming their own communication networks. The brain may compute through both electrical (neuronal) and chemical (glial) networks at once — a shift that overturned the old view of glia as passive.