Abstract: Objective To observe the effect of the soft tissues injury around atlantoaxial joint on memory abilities of mice.Methods 44 mice were divided into the model group and control group with 22 animals in each group.The soft tissues around atlantoaxial joint were injured in the model group by surgery between the first and the second cervical vertebrae.The changes of learning and memory of mice were observed with step-down avoidance test,water-maze test and hole-board test;the expression of caspase-3 in hippocampus was observed by immunohistochemical staining.Results Compared with the control group,escape latency was longer and wrong times were more in water-maze test of the model group(P<0.01). In step-down avoidance test of the model group,the reaction period prolonged and wrong times increased obviously(P<0.01).In hole-board test,the latency period prolonged and the times of extending the holes decreased significantly(P<0.01).Degenerated or dead neuron in hippocampus of surgery-treated mice was found scatteredly or continuously with HE staining,the expression of caspase-3 protein was showed positive with immunohistochemical staining.Conclusion The soft tissues injury arround atlantoaxial joint can induce abnormality of the stability of cervical vertebra,which aggravated the aging process of the mice and decreased abilities of learning and memory.

Key words: soft tissue, learning and memory, atlantoaxial joint