| Abstract: | Both the mitotic index after colchicine block and the fraction of cells labeled by a short exposure to [3H]TdR indicate that the rate of proliferation in cultures of murine neuroblastoma cells (N18 clone) decreases only after several days of maintenance in serum-deficient medium. Viable cell counts remain constant because of a large increase in the number of cells which die and are shed into the medium. Therefore, the neurite formation and enzyme induction which occur under these conditions cannot be caused by inhibition of DNA synthesis. |
