The maintenance effect of β-amyloid injection in the CA1 region of hippocampus on learning and spatial memory in adult male rats

Alzheimer’s disease is one of the most common neurodegenerative diseases that lead to the progressive loss of mental, behavioral and learning abilities. The aim of this study was to investigate the maintenance effect of β-amyloid1-42 (Aβ) injection in the CA1 region of hippocampus on learning and spatial memory of adult male rats using the Morris water maze test.
In this study, 42 adult male Wistar rats were randomly divided into control (intact), sham (Aβ solvent) and Aβ-injected groups (5 μg/μl). The β-amyloid and its solvent were bilaterally injected into the CA1 region of rat's hippocampus. The first recipient group of Aβ and its solvent after 6, the second group after 11 and the third groups after 31 days were trained by the Morris water maze test.
During 4 training days and also in probe and visible tests, there was no significant difference between control and sham groups. The results of the learning steps in Aβ groups showed that traveled distance and escape latency to find the hidden platform was significantly increased compared with the sham groups, but there was no significant difference in the probe and visible tests between these groups.
It seems that long exposure to Aβ can lead to more memory and learning loss in animals with Alzheimer.