Fig. 6

Region specific pre-synaptic puncta loss in TgCRND8 slices. a, b Representative maximal intensity projections of z-stacks taken from the CA1 field (same location as Aβ positive axonal swellings) in 5-week old WT (a) and TgCRND8 (b) slices. The presynaptic marker synaptophysin (SYP) is stained green, whilst the postsynaptic marker PSD95 is stained red. c, d, e Quantification of the z-stacks was performed using an image J plugin (available on request from: c.eroglu@cellbio.duke.edu). There was a reduction in synaptophysin positive puncta in TgCRND8 slices (p = 0.025) (c) whilst the number of PSD95 positive puncta was unchanged between genotypes (p = 0.25) (d). The number of colocalised puncta (Synaptophysin/ PSD95 positive) was also reduced (p = 0.038) (e). f, g Z-stacks taken from the CA3 field (largely unaffected by Aβ-positive swellings) in 5-week old WT (f) and TgCRND8 (g) slices revealed no such differences in synaptophysin positive puncta (p = 0.48) (h), PSD95 (p = 0.69) (i) or colocalised structures (p = 0.75) (j). Analysis for each region consisted of n = 8 individual membranes, 3 slices per membrane (slices on each membrane are from different mice). For each membrane value, data was averaged from 3 slices, with 5 z-stacks per slice) with P values calculated using a students t-test