Neuregulin-1, a key axonal signal that drives Schwann cell growth and differentiation.

Interactions between neuronal and glial cells are crucial for establishing a functional nervous system. Many aspects of Schwann cell development and physiology are regulated by neuronal signals; possibly the most spectacular is the elaboration of the myelin sheath. An extensive line of research has revealed that one neuronal factor, termed "neuregulin", promotes Schwann cell growth and survival, migration along the extending axon, and myelination. The versatility of glial responses elicited by this factor is thus clearly astounding.