Figure 4.

Visual stimulation with light flickering at 40 Hz had no effect on endogenous levels of amyloid β (Aβ) in the mouse hippocampus. A, The endogenous levels of Aβ peptides in the hippocampus of 33-week-old control C57BL/6 and 5xFAD mice were determined by Aβ immunostaining. Bar indicates 200 μm. B, Summary of the results in A showing the relative area occupied by Aβ in the hippocampus. n = 4 mice per group. * indicates p < 0.05 when compared by unpaired t test. C, The endogenous levels of Aβ in the hippocampus of 5xFAD mice subjected to daily 1-h visual stimulation with continuous light or light flickering at 24, 40, or 80 Hz for five weeks were determined by Aβ immunostaining. Bar indicates 200 μm. D, Summary of the results in C showing the relative area occupied by Aβ in the hippocampus. n = 4 mice per group. n.s. indicates no significant difference when compared by one-way ANOVA.