Behavioral and neurochemical effects of the intrahippocampal co-injection of β-amyloid protein1-40 and ibotenic acid in rats

The authors investigated the effects of bilateral intrahippocampal co-injection of Abeta1-40 (4 mug for each side) with ibotenic acid (Ibo, 2 mug for each side) on rats' performance in the open field behavior, Y-maze, and passive avoidance task, and also examined some neurochemical changes in hippocampus two weeks after the co-injection. The results showed that the co-injection of Abeta1-40 with Ibo induced a decrease in exploratory activity and a significant decline in learning-memory ability of the tested rats (p<.01). The neurochemistry changes induced by the co-injection included a significant decreased in membrane fluidity of hippocampal mitochondria (p<.01), a significant decrease in the activity of SOD (p<.01), and a remarkable increase in the content of MDA (p<.01). These results suggest that the co-injection of Abeta1-40 with Ibo may induce an increase of hippocampal damage by peroxidation, and a serious learning and memory impairment of the rats. The results also suggest that the co-injection of Abeta1-40 with Ibo may provide a useful animal model for Alzheimer's disease (AD) research.