ABSTRACT
The neuregulins (NRGs) are a family of proteins containing an epidermal growth factor (EGF)-like motif that mediates important functions not only in the nervous system but also in the heart, breast and other organ systems. NRG1 was first found to function in the nervous system in the proliferation of Schwann cells, and in the regulation of nicotinic acetylcholine receptor (AChR) transcription at the neuromuscular junction (NMJ). NRGs have multiple biological functions. In the brain, NRG signaling regulates early fate determination, differentiation, migration, synaptic activity of target cell and the expression of other neurotransmitter receptors and survival of satellite cells, Schwann cells and oligodendrocytes. There is also evidence for involvement of NRGs signaling in the pathogenesis of disease, including breast cancer, multiple sclerosis, traumatic brain injury and Hirschsprung's disease. Especially, both NRG1 and ErbB4 have emerged as susceptibility genes of schizophrenia. In this review, I will summarize the latest findings regarding the spectrum of NRG-ErbB action and signaling pathways in the developing and adult nervous system.