Non-fibril form induces morphological changes in neurons.

(A, B) Disturbed differentiation of neuron-like PC12 cells by the non-fibril form. Representative images (A) and quantification of the total length of neurites (B) of PC12 cells in the presence of FITC and the non-fibril form after NGF-induced differentiation. The numbers of biological replicates were 6 for all groups and 2–5 images were taken from each biological replicate. n = 67 and 60 cells for FITC and the non-fibril form, respectively. The average for all cells per biological replicate was used for the Mann-Whitney U test. (C, D) Neuron loss in the hippocampus by the non-fibril form. Representative images are shown in (C). Quantification of the thickness of the pyramidal cell layer (vertical bars in the pictures) in the CA3c region of the hippocampus in Nissl-stained coronal brain sections of mice (D). FITC and the non-fibril form were injected into the hippocampus a month prior. Arrows indicate the regions with extensive neuronal loss. n = 8 and 12 for FITC and the non-fibril form, respectively. ANOVA was applied. Error bars represent SD. *p < 0.05; **p < 0.01. Scale bars, 20 μm (A) and 100 μm (C).