Dynamin mediates oligomeric Aβ42-induced neurotoxicity. A. N2A cells were pre-treated ± 10 mM genistein for 1 hour, treated with 10 μM oAβ42 for 24 hours ± genistein, and assayed for neurotoxicity as described in Figure Legend 1. Significant difference (p < 0.01) between cells ± genistein is indicated by an asterisk (*). B. N2A cells were transiently transfected with dynamin wild type, dominant-negative K44A mutant expression plasmids, or vector control; treated with 10 μM oAβ42 for 24 hours and assayed for neurotoxicity. Significant difference (p < 0.01) between cells ± dominant-negative K44A mutant are indicated by an asterisk (*). Inset, expression levels of c-myc tagged dynamin were characterized by anti-myc antibody with Western blot analysis with an equal amount of lysate from cells transfected with vector, dynamin wild type, or dynamin dominant-negative K44A mutant. C. N2A cells were transiently transfected with dynamin wild type or dominant-negative K44A mutant expression plasmids. 48 hours post-transfection, cells were treated with 10 μM oAβ42 for 30 minutes, and stained for Aβ with Aβ42 specific antibody (Invitrogen, green). Transfected cells were identified by anti-myc antibody (Abcam, red). Nuclei appear blue as detected by DAPI staining. Cells were individually outlined and mean fluorescence intensity of Aβ signals were quantified with NIH image software. Significant difference in Aβ levels (p < 0.01) between cells with dynamin wild type and K44A mutant is indicated by an asterisk (*).