Growth Control of Nerve Cells by a Protein Factor and Its Antiserum

Abstract

Evidence is presented that sympathetic nerve cells of birds and mammals are receptive to the growth promoting effects of a protein (NGF) which was isolated from some mouse sarcomas, snake venom and mouse salivary glands. This same protein is a normal constituent of the sympathetic cells and is present in the blood and body fluids of a variety of vertebrates, man included. An antiserum to the NGF selectively destroys the sympathetic nerve cells of newborn animals without affecting other nerve cells or organs. The "immunosympathec-tomized" animals are comparable to controls in growth and viability. These results give evidence for the essential role of this particular protein in the growth, differentiation, and maintenance of sympathetic nerve cells. They also suggest that other nerve cells might also depend upon specific factors for their differentiation and growth. These results are discussed in the general framework of neurogenetic problems.