Fig. 6

Calpain-1 activities in AD brain correlate with Aβ1-42 burden, cytoskeletal protein cleavage and kinase activities. Scatter plots show the correlation between amounts of active calpain-1 and (a) Aβ1-42, (b) calpain- and caspase-cleaved α-spectrin fragments and (c) p25 in all tissue samples. Correlation analysis was used to generate correlation co-efficients (r values) and significance. *p < 0.05, **p < 0.01, ***p < 0.001. d Qualitative plot illustrating the stage of disease at which changes were observed in calpain-1 activity, total APP protein, Aβ1-42 amounts, active cdk5 (p25/cdk5), active GSK-3 (reductions in pGSK-3), p-tau (tau phosphorylated at Ser396/404), pre- (synapsin-1) and post- (PSD-95) synaptic marker amounts. Relative amounts are indicated in grey scale, with low protein amounts signified by pale shading and large amounts by dark shading