GPHN and Alzheimer disease: Further in agreement with the FDT analyses, the ratio of large-to-small synaptosome-like particles was strongly reduced in AD and DS (F (2,13) = 29.83, P < 0.0001 vs control) (Fig. 4f), and the large/small ratio from the whole slice was linearly correlated to the high/low immunoreactivity for PSD-95 and GPHN in layers 1 and 2 combined (R2(16) = 0.72, P < 0.0001) (Fig. 4g).