OBJECTIVE: After intracerebroventricular injection of different concentrations of amyloid Aβ25-35, observe the changes in the learning and memory ability of the Morris water maze in rats, determine the optimal concentration of Aβ25-35 injection for AD model rats, and conduct inspections.
Method: Male SD rats were randomly divided into sham operation group and model group. The injection concentrations of Aβ25-35 in the model group were 2, 4, and 8μg/μL, respectively. Refer to "Rat Brain Stereotactic Atlas", select the right ventricle and inject aggregated Aβ25-35 to create an AD rat model. Seven days after successful modeling, the Morris water maze was used to test the changes in the learning and memory abilities of each group of rats.
Result: Comparing the average swimming speed, there is no significant difference between rats in each group (P \u003c0.05). The results of the escape latency showed that compared with the sham operation group, the escape latency of the model group was significantly increased, and the difference was statistically significant (P0.05). Compared with the sham operation group, the target quadrant activity time and distance of rats injected with different doses of Aβ25-35 in the model group were significantly reduced, and the difference was statistically significant. (P0.05). The results of space exploration showed that rats injected with different doses of Aβ25-35 passed the platform of the model group significantly less than the sham operation group, and the difference was statistically significant (P0.05).
Conclusion: When the Aβ25-35 protein is injected into the cerebral ventricle unilaterally to establish a rat AD model, the recommended injection concentration of Aβ25-35 is 4μg/μL.