Local sprouting of neurites from cultured PC12D cells in response to a concentration gradient of nerve growth factor

PC12D cells, a subline of PC12 cells, extend neurites very rapidly in response to NGF, even when RNA synthesis is blocked. Several minutes after the initiation of a concentration gradient of NGF from a micropipette in the vicinity of PC12D cells, clear projections emerged from cells on the side facing the micropipette while no significant changes in morphology were observed on the other side of cells. A control solution administered from a micropipette did not produce any changes in morphology. Longer exposure to the gradient of NGF of aggregates of PC12D cells increased the length of neurites extending toward the source of NGF. The observations indicate that the sprouting of neurites occurs locally in regions of PC12D cells that are exposed to an elevated concentration of NGF.