Immunohistochemical characterization of MARK1-4 protein expression in the hippocampus. (A-H) Photomicrographs of immunohistochemical staining from the CA2 area of representative NDE and AD cases (#9, #7, #13, #18 and #34) with specific antibodies for each MARK isoform. Neurons containing granulovacuolar degeneration bodies (GVDs) are marked with arrowheads and magnified in insets. MARK1 and MARK2 antibodies reveal a diffuse cytoplasmic staining but no positive staining in GVDs (red arrowheads). Black arrowheads indicate positive staining in GVDs as this is observed in all GVDs with the MARK4 antibody and in some but not all GVDs with the MARK3 antibody. Scale bar: 50 μm. (I) Quantification of the number of MARK3, MARK4 or CK1δ neurons with granular immunoreactivity in the CA1-CA2 area or CA3-CA4 area. n = 4–5 NDE; 7–10 AD. Data depicts means ± SEM. *p < 0.05, **p < 0.01 by Student’s unpaired t-test. (J) Data in (I) plotted against Braak stage. n = 1(Br0); 2-3(Br1); 1(Br2); 2(Br4); 2-5(Br5); 3(Br6).