Neuronal Growth Factors

A host of environmental factors regulate the embryonic development of neurons. In adults, the survival of neurons, the regeneration of damaged axons, and plastic changes in axonal arborization are also controlled by a complex array of environmental cues. An important category of regulatory influences involves target-derived hormone-like peptides act­ ing on neuronal cell surface receptors. Nerve growth factor (NGF) was the first such factor to be characterized (LEVI­ MONTALCINI and HAMBURGER 1