The nerve growth factor and nervous system development

The 20th century has witnessed a slow but progressive convergence and tightening between neurological and psychological studies. Nowadays, the notion that both mental and neurological functions are the expression of the same organ is widely accepted. In this short review we summarize some aspects of the structure and function of a protein molecule, the nerve growth factor, whose discovery and further characterization has contributed, although in a different fashion, to this tightening. For lack of space we will not enumerate the studies that have contributed to the “mind” aspect of NGF story but simply confine our review to its role in development. The development of the nervous system requires synchronized and localized processes of cell survival and of programmed cell death modulating cell number and the accurate target innervations in structurally and functionally distinct regions of the brain. The neurotrophin nerve growth factor (NGF), plays both activities in neuronal development through cell survival and cell death signaling. In particular, it is essential for survival and differentiation of selective populations of neurons during development including sensory, sympathetic (Levi-Montalcini, 1987) and basal forebrain cholinergic neurons (BFCNs). Lack or altered timing of its supply or distribution to these neuronal populations is accompanied by death of the target neurons. Moreover, it has been recently reported that NGF regulates the axis rotation, an evolutionarily conserved process in vertebrates which is crucial for the proper morphogenesis of internal organs.