Effect of β amyloid protein on learning-memory and cerebral cortex lipofuscin content in the aging model of rats

To study effect of β amyloid protein(βAP, 4 μg in 1 μL, injected into each side of hippocampus at d 28) on learning and memory in the aging rats induced by D galactose(D Gal, ip, 50 mg·kg -1 ·d -1 , for 42 d). The behaviors of rats were measured by using open field, Y maze and one trial passive avoidance response, and the lipofuscin content in cerebral cortex were measured by spectrofluoro photometer. The results showed that D Gal and βAP alone significantly decreased the spontaneous activities and responses to novel environment in the open field, and remarkably attenuated the abilities of learning memory, increased the lipofuscin content in cerebral cortex. The combination of D Gal and βAP enhanced the above mentioned effects, which suggests that they are cooperative in impairing learning and memory.