The regulation of nerve fiber length by intercalated elongation and retraction

Cell body movements were observed in cultures of rat sympathetic neurons that were accommodated by the elongation of neurite segments intercalated between the cell bodies and distal neurites. The elongation may represent growth of the neurites in response to mechanical tension arising from the cell body movements. Preliminary observations also suggest that neurites made slack may actively shorten. Control of nerve fiber length by mechanical tension could allow the nervous system to readily accommodate changes in the size and shape of the organism that occur during development and growth. It is possible that nerve growth factor promotes nerve fiber elongation indirectly through tension generated by growth cone movements.