Amyloid-Beta Induced Changes in Vesicular Transport of BDNF in Hippocampal Neurons

Figure 2

Expression of hAPP reduced vesicular transport of BDNF. Dissociated hippocampal neurons of C57BL/6 mice were cotransfected at 10 DIV with BDNF-mCherry and hAPP-YFP. The dynamic behavior of BDNF-containing vesicles was analyzed by live cell imaging 1–3 days after transfection. (a) Representative picture of BDNF-containing vesicles at different time points of time-lapse recording. Red and green circles mark BDNF-containing vesicles showing a directional movement. (c) Bar diagram indicates the mean percentage of immobile BDNF-containing vesicles in control neurons or in neurons transfected with hAPP during the whole observation period. Tables below bar diagram give the mean value of the incidence of immobile vesicles for day 1, day 2, and day 3. Transient expression of hAPP significantly changed the proportion of immobile vesicles. (d) Transport dynamics of anterogradely directed BDNF-containing vesicles. Bar diagrams show the mean value of the indicated motional properties during the whole observation period. Tables below bar diagrams give the mean value of the indicated motional property for day 1, day 2, and day 3. The overall average speed as well as the average speed during motion was significantly reduced in neurons transfected with hAPP compared to control neurons. While the characteristics of BDNF-containing vesicles were similar in neurons expressing hAPP and control neurons at day 1 after expression of hAPP, the average speed of BDNF-containing vesicles was significantly reduced in neuronal cultures transfected with hAPP at day 3. (e) Transport dynamics of retrogradely directed BDNF-containing vesicles. The motional properties as indicated were significantly changed in neurons transfected with hAPP compared to controls (, , ; two-way ANOVA followed by pairwise multiple comparison). Error bars represent SEM.

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