The Ecology of Humans (26-25) Oligodendrocytes


Oligodendrocytes are somewhat similar to Schwann cells in being in the myelin of axons. Whereas Schwann cells are part of the peripheral nervous stem, oligodendrocytes are in the central nervous system.

Oligodendrocytes are smaller than Schwann cells. Oligodendrocytes are abundant in the cortex astrocyte mass, which is the white matter of the brain. Rather than affecting brain chemicals, oligodendrocytes influence neuronal signaling rhythms via their presence in myelin.

The brain churns out new oligodendrocytes while learning new skills. These newcomers wrap extra myelin around the axons of neuronal circuits under construction.

Conversely, unused neural circuits wither because oligodendrocytes ignore them. The brain rewires itself based upon glial activity.

Myelin accelerates the transmission of electrical signals along axons. A signal takes 30 milliseconds to cross the brain on myelinated axons; 10 times faster than on un-myelinated axons.

Information processing relies upon signal synchrony, which delays disrupt. Modest additional thickness of myelin layers on axons tweak the timing of the brain’s electrical signals enough to bolster learning and memory.

Multiple sclerosis is a debilitating inflammatory disease in which myelin is damaged: disrupting nervous system communication, which results in a wide range of physical and mental disabilities. The cause of the disease is destruction of the glia that provide myelin sheath production.