Staurosporine-treated neurons undergo different outcomes when SYTO 13 and Hoechst are used in time-lapse imaging. (A) Neurons stained with Hoescht (blue; top panels) visually undergo chromatin condensation within 4 h and remained PI-negative. In contrast, neurons visualized with 500 or 5 nM SYTO 13 (green) became PI-positive (red) by 2 h, without visual evidence of chromatin condensation. White arrows indicate cells that became PI-positive in each frame. Condensed, PI-positive nuclei (purple in top panels, red in middle and bottom panels) observed at time 0 represent cells that died during initial plating. In bottom panels, the increased gain needed to clearly image nuclear structure resulted in PI-positive nuclei developing an orange hue. (B) Planimetric quantitation of nuclear size measured longitudinally through the 6 h experiment. * represent p < 0.05; ^ represents p < 0.01.