Fig. 1. Inhibition of GSK-3 leads to the formation of multiple axon-like processes. (A) Hippocampal neurons were incubated without (control) or with different GSK-3 inhibitors from the time of cell attachment up to 48 hours. Axons were visualised using an anti-Tau-1 antibody. (B) Western blot showing cytoplasmic ß-catenin accumulation in dissociated hippocampal neurons after GSK-3 inhibition. (C) Quantification of the effects of GSK-3 inhibition on the percentage of neurons bearing one or multiple axon-like neurites (percent of stage-2 neurons not shown). For each treatment, 200-300 neurons of different hippocampal preparations were counted (mean ± s.e.m., ^**P<0.001; ^*P<0.002). (D) Control (bottom left two panels) and SB21673-treated (bottom right two panels) neurons were fixed and endogenous PMGS was detected in conjunction with Tau-1. PMGS-fluorescence along the neurites was measured, normalised and sorted according to intensity. In control neurons the fluorescence in the axon was set to 100% (mean ± s.e.m., ^**P<0.001; ^*P<0.01). Bars, 10 µm.