Fig. 1

pS25 and pS1201 Abs labeled the growing axons in the cultured neurons. a and b Immunofluorescent studies of the cultured mouse cortical neuron using pS25 or pS1201 Abs (green) with MAP 1B Ab (red). Each phospho-specific Ab showed the preferentially stronger immunoreactivity to the axon, than MAP 1B Ab itself. Scale bar: 50 μm. c The ratio of the mean signal intensity (pS25 or pS1201 vs MAP 1B) of the axon and the dendrites in each neuron were compared. Data are shown as mean ± SD; n = 10; *p < 0.05 by paired t test. d The white area indicates the region of interest. From the axonal tip to 170 μm proximal, the signal intensity was measured. e Profiles of the ratio of the fluorescence intensity (pS25/MAP 1B and pS1201/MAP 1B) from the axonal tip to the proximal part of the axon were comparable. Thick lines indicate mean values, and thin lines indicate SD; N = 10. f and g Immunostaining of cultured mouse cortical neurons using pS25 or pS1201 Abs (green) with rhodamine phalloidin for F-actin (red) and Tuj-1 Ab for β-III tubulin (blue). pS25 and pS1201 Abs labeled the tubulin-positive area of the axon more intensely than the actin-positive area. Scale bar: 25 μm