Fig. 2

YKL-40 immunoreactivity pattern and colocalization analyses in different tauopathies. Representative images of the triple immunofluorescence studies performed with YKL-40 (red), GFAP (green) and tau (magenta) antibodies. Nuclei are marked in blue. All four tauopathies investigated, a–e AD, f–j PiD, k–o CBD and p–t PSP, showed a cytoplasmic astroglial expression pattern of YKL-40. Scale bar = 20 μm. u Colocalization analysis confirmed that approximately 80% of YKL-40 colocalized with GFAP in all tauopathies. No colocalization was detected between YKL-40 and tau in any condition. As expected, non-AD tauopathies showed an overlap between tau and GFAP. ***p < 0.001; *p < 0.05