AIM To determine whether
microinjection of β
amyloid peptide fragment 25～35 (Aβ25～35 ) into rat
hippocampus induces the
learning and memory dysfunction.METHODS Microinjection of Aβ 25～35 into hippocampus induced the rat learning and memory dysfunction. Step down test, Shuttle box test, and Morris water maze test were used to evaluate rat learning and memory function;The sections were stained with haematoxylin eosin (HE),the amyloid deposits were detected using Congo Red and silver.RESULTS The latency of Aβ 25～35 treated rats shortened,the stimulating time prolonged,and the numbers of errors increased in the step down test;Shuttle box test showed that Aβ 25～35 caused the latency and numbers of active escape reduction and the numbers of passive avoidance increase; Also in morris water maze, Aβ25 35 induced an impairment in rat spatial resolution; In Aβ 25～35 treated group, a significant decrease in the numbers of neurons in cortex and hippocampus,a massive glial reaction and neurophilic phenomenon were detected by HE staining; the positive vascular amyloidosis by Congo red and fibrils by Ag staining were also observed.CONCLUSION Microinjection of Aβ 25～35 into rat hippocampus may induce the learning and memory dysfunction and pathological changes which were similar to that found in
Alzheimers disease (AD) brain.
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