AIM: To study the correlation of β-amyloid(Aβ)plaques in retinas from Alzheimer's model mice in different months and progression of disease.

METHODS: Six-month(n=6)and twelve-month(n=6)old Alzheimer's model mice, together with six-month(n=6)and twelve-month(n=6)old C57 mice were in this experiment. Morris water maze test was to assess the spatial memory. After intragastrical administration of curcumin for consecutive three days, the Aβ plaques in retinas(n=48)from all mice(n=24)were detected by noninvasive in vivo optical imaging.

RESULTS: Morris water maze test: compared with the six-month control group(C6), six-month model mice(AD6)swam longer(P<0.05); and AD6 swam longer distance and experienced more crossing times than C6(P>0.05); compared with the twelve-month control group(C12), twelve-month model mice(AD12)swam longer, swam longer distance(P<0.05)and experienced more crossing times(P>0.05); compared with the six-month model mice(AD6), twelve-month model mice(AD12)swam longer, swam longer distance and experienced more crossing times(P<0.05). Moreover, the result of retinal Aβ plaques: We identified retinal Aβ plaques in postmortem from AD6 and AD12. Two six-month model mice had been detected retinal Aβ plaques, thus the positive rate of retinal Aβ plaques in six-month model mice was 33%; And six twelve-month model mice had been detected retinal Aβ plaques, thus the positive rate of retinal Aβ plaques in twelve-month model mice was 100%; Plaques were undetectable in age-matched non-AD individuals neither in six-month or in twelve-month; the positive rate of retinal Aβ plaques in AD12 was higher than AD6(P<0.05).

CONCLUSION: Six-month model mice(AD6)had already a decline of cognition; and the illness gradually increased with the extension of the disease, and the positive rate of retinal Aβ plaques is increasing with progression of Alzheimer's disease.