Fig. 3

PS1/γ-secretase present in the pre- and post-synaptic terminals. a Confocal microscopy imaging shows co-localization of PS1 with Syt1 (left) and with synapsin1 and vGlut1 (right) in presynaptic compartments of isolated synaptoneurosomes (SNSs, arrowheads). Arrows show MAP2-positive post-synaptic buttons. Insert on the left shows a bright field image of isolated SNS. b Western blot analysis of PS1 CTF, Nct, Pen-2, Syt1 and β actin as a control in total homogenate (H) and synaptoneurosome (S) fractions from wild type mouse brain. Enrichment of the γ-secretase components in SNS vs. total brain homogenate is quantified. Data are presented as mean ± SEM, n = 4. Statistical significance was determined using the unpaired student t-test; * p < 0.05, *** p < 0.001. c Electron micrographs of synaptic terminals from mouse cortex immunostained for PS1 (gold particles). Red circles and arrows indicate positive staining in presynaptic and postsynaptic compartments, respectively. PS1 presenilin 1, Syt1 synaptotagmin 1, vGlut1 vesicular glutamate transporter 1, MAP2 microtubule-associated protein 2, CTF C-terminal fragment, Nct nicastrin, Pen-2 presenilin enhancer 2