Distribution of dendritic morphologies among DCX-positive cells. A, among all DCX-positive cells of the SGZ, 22% are in categories A and B, the actively dividing stages (cf. Fig. 2). If categories C and D are included in this consideration the fraction of potentially proliferative DCX-positive cells is about one third (cf. Fig. 5). More than 50% of the DCX cells are in category E. If adult hippocampal neurogenesis is increased by voluntary wheel running or kainic acid-induced seizures, at the peak of cell proliferation the distribution of DCX-positive cells is not changed compared to control conditions. B depicts the absolute numbers. Across the categories there is an increase in cell numbers. C, stress associated with swimming in the Morris water maze was found downregulate adult neurogenesis and affected dividing precursor cells . Analysis of dendritic morphology of DCX-positive cells from that study revealed again no change in the distribution of dendritic morphologies. D shows the absolute values.