Schwann cells–axon interaction in myelination

• Schwann cells–axon interaction is crucial for myelination and nervous system homeostasis.
• Schwann cells and axon are in intimate contact throughout development.
• Neuregulin 1 (NRG1) is the key axonal growth factor controlling PNS myelination.
• Schwann cells control metabolic support of the axons.

The remarkable interaction between glial cells and axons is crucial for nervous system development and homeostasis. Alterations in this continuous communication can cause severe pathologies that can compromise the integrity of the nervous system. The most dramatic consequence of this interaction is the generation of the myelin sheath, made by myelinating glial cells: Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. In this review I will focus on signals coming from axons in the first part and then on those from Schwann cells that promote the formation and the maintenance of peripheral myelin. I will discuss their inter-relationship together with seminal and important advances recently made.