Disruption of the Syp/VAMP2 complex.

<p>(<b>a</b>) Immunoprecipitation of VAMP2 from hippocampal extracts assayed by western blotting for VAMP2 and Syp. A band of 19 kDa corresponding to VAMP2 and a band of 38 kDa, corresponding to Syp were detected in all conditions. A reduction in immunoprecipitated Syp was induced by Aβ42 (lane 3) compared to control (scrambled Aβ, lane 4). (<b>b</b>) The intensity ratio between Syp and VAMP2 is reduced in the presence of Aβ42 (n = 3, student t-test p = 0.0026). (<b>c</b>) co-labelling for Syp and VAMP2 in untreated hippocampal neurons, in neurons treated either with Aβ42 and allowed to recover for 15 min (<b>d</b>) or with scrambled peptide (<b>f</b>) display a significant degree of co-localisation. (<b>e</b>) Aβ42 treated neurons allowed to recover for 2 hrs display stretches of VAMP2 immunoreactivity (indicated by arrows). (<b>g</b>) Quantification of the extent of co-localisation between Syp and VAMP2. Aβ42 treated neurons left to recover for 2 hrs showed decreased level of co-localisation (M = 0.85±0.09, n = 24) compared to control (M = 0.961±0.03, n = 24, student t-test ** = 0.0003), whereas neurons left to recover for 15 min (M = 0.99±0.02, n = 24) or incubated with the scrambled peptide (M = 0.99±0.01, n = 18) did not display differences compared to control. Scale bar = 10 µm.