Oligodendrocyte myelin-producing function

Oligodendrocytes are present in the CNS as well and wrap around axons to form a myelin sheath. Myelin wraps into concentric layers that spiral around the axon. Gaps in the oligodendrocytes are the nodes of Ranvier, where the membrane maintains contact with extracellular fluid. The nodes serve to propagate the action potential in myelinated axons. Schwann cells perform an analogous function, myelinating axons in the peripheral nervous system. Not all neurons are myelinated, but myelination increases the metabolic efficiency of action potentials. Demyelination of neurons produces deficits in neuronal conduction, as is seen in multiple sclerosis. 

The process of myelination represents one of the clearest examples of cell-cell cooperation. Neither axons nor myelin-forming cells can functionally differentiate to completion without each other (Trapp et al., 2004), although oligodendrocytes produce significant amounts of myelin-like membrane in neuron-free culture. 

Backstrom, B.T., Brockelbank, J.A., and Rehm, B.H.A. (2007) Recombinant Escherichia coli produces tailor-made biopolyester granules for applications in fluorescence activated cell sorting functional display of the mouse interleukin 2 and myelin oligodendrocyte glycoprotein. BMC Biotech., 7, 3, Article Number 3. 

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