中文摘要：

老化通常指生物体生长发育成熟以后,随年龄增加生理机能逐渐减退,内环境稳定性下降,组织器官逐渐发生退行性改变,最终走向衰老、死亡的过程。神经系统老化是神经元退行性病变形成的基础和条件。由于神经生长因子（nerve growth factor,NGF）与中枢神经系统胆碱能神经元的存活和可塑性调节密切相关,所以NGF在神经系统老化和神经退行性变疾病如老年性痴呆（Alzheimer’s disease,AD）的发生发展过程中发挥重要作用。本文综述了NGF在脑老化中的变化及其与AD发病机制的关系。

英文摘要：

Aging usually refers to the physiological function reduced with age-increasing after the growth and development of a mature organism, internal environmental instability, tissues and organs undergoing gradually degeneration, and ultimately changing towards aging. Nervous system aging is the foundation and conditions of neuro-degenerative diseases. Nerve growth factor （NGF） and eholinergic neurons in central nervous system survival and plasticity are closely related to regulation, so NGF plays an important role in the nervous system aging and development of nem＇o-degenerative diseases such as Alzheimer＇s disease （AD）. In this paper, we review the changes of NGF during brain aging and its relationship between the pathogenesis of AD.