Staurosporine induces hyperpolarization of rat hippocampal neurons. a, Cultured rat hippocampal neurons exposed to STS for the indicated period of time were loaded with TMRE (100 nm, 15 min), and fluorescence was quantified. The TMRE uptake increased significantly at all time points measured. Data are means ± SEM from n = 27–150 neurons fromn = 5–20 separate experiments per time point. Different from controls *p < 0.05.b, STS-induced increase in TMRE fluorescence was not inhibited by blocking outward potassium currents. Hippocampal neurons were treated with 300 nm STS for 6 hr. Subsequently, cultures were exposed to HBS or HBS + TEA + clofilium tosylate (Clo) for a further 15 min. After a 10 min loading period, cellular TMRE fluorescence was acquired. Data were not expressed as an SD and therefore were presented in median/quartile form and represent values from n = 82–185 cells. *,^#p < 0.05 compared with respective controls.