The morphological abnormalities observed in Tg neurons and in TgCM-treated neurons are improved by VIVIT-GFP. A, Representative images of Wt and Tg GFP-labeled neurons (left) and dendrites (right) at 18 DIV. Scale bar, 100 μm. B, GFP-transfected Tg neurons present a lower spine density compared with Wt littermate cells, but the number of spines is significantly improved when Tg neurons were previously transfected with VIVIT-GFP. C, In addition, Sholl's plot analyses of Wt and Tg cultures show an overall decreased complexity of the dendritic arborization in Tg neurons overexpressing GFP compared with Wt neurons. The simplification of the dendritic arbor is fully corrected when Tg neurons were transfected by VIVIT-GFP and it reaches the level of complexity observed in Wt neurons (p = NS compared with Wt neurons transfected with GFP). D, Representative images of wild-type cortical neurons (left) and dendrites (right) expressing GFP or VIVIT-GFP after treatment for 24 h with WtCM, TgCM, or depleted TgCM. Scale bar, 100 μm. E, Dendritic spine quantification demonstrates that a short exposure to oligomeric Aβ leads to a significant decrease of their density, whereas spines are unaffected when WtCM was applied. However, the spine density is maintained when TgCM-treated neurons overexpress VIVIT-GFP or when Aβ peptides were previously immunodepleted from the medium using the 6E10 antibody. *p < 0.01, **p < 0.0001 and ***p < 10−10. (n > 40 cells per condition).
