All the hallmarks of ageing are observed in the brain, and its cells, especially neurons, are characterized by their remarkably long lifetime. Like any organ or system, the brain is exposed to ageing processes which affect molecules, cells, blood vessels, gross morphology and, uniquely for this organ, cognition. The preponderant cerebral structures are characterized by the cellular processes of neurons and glial cells and while the quantity of cerebral interstitial fluid is limited, it is now recognized as playing a crucial role in maintaining cerebral homeostasis. Most of our current knowledge of the ageing brain derives from studies of neurodegenerative disorders. It is interesting to note that common features of these disorders, like Tau, phosphoTau and amyloid peptide accumulation, can begin relatively early in life as a result of physiological ageing and are present in subclinical cases while also being used as early-stage markers of neurodegenerative diseases in progression. In this article, we review tissue and cellular modifications in the ageing brain. Commonly described macroscopic, microscopic and vascular changes that in the ageing brain are contrasted with those seen in neurodegenerative contexts. We also review the molecular changes that occur with age in the brain, such as modifications in gene expression, insulin/insulin-like growth factor 1 signalling dysfunction, post-translational protein modifications, mitochondrial dysfunction, autophagy and calcium conductance changes.

在大脑中可以观察到衰老的所有标志，其细胞，尤其是神经元，具有非常长的寿命。像任何器官或系统一样，大脑会暴露在老化过程中，这些过程会影响分子、细胞、血管、大体形态，以及这个器官特有的认知。占优势的大脑结构以神经元和神经胶质细胞的细胞过程为特征，虽然大脑间质液的数量有限，但现在被认为在维持大脑稳态方面起着至关重要的作用。我们目前对大脑老化的大部分知识都来自对神经退行性疾病的研究。有趣的是，这些疾病的共同特征，如 Tau、磷酸 Tau 和淀粉样肽积累，由于生理老化，可以在生命的较早时期开始，并且存在于亚临床病例中，同时也被用作进展中的神经退行性疾病的早期标志物。在本文中，我们回顾了衰老大脑中的组织和细胞修饰。老化大脑中常见的宏观、微观和血管变化与神经退行性环境中的变化形成对比。我们还回顾了大脑中随年龄增长而发生的分子变化，例如基因表达的改变、胰岛素/胰岛素样生长因子 1 信号传导功能障碍、翻译后蛋白质修饰、线粒体功能障碍、自噬和钙电导变化。在本文中，我们回顾了衰老大脑中的组织和细胞变化。老化大脑中常见的宏观、微观和血管变化与神经退行性环境中的变化形成对比。我们还回顾了大脑中随年龄增长而发生的分子变化，例如基因表达的改变、胰岛素/胰岛素样生长因子 1 信号传导功能障碍、翻译后蛋白质修饰、线粒体功能障碍、自噬和钙电导变化。在本文中，我们回顾了衰老大脑中的组织和细胞变化。老化大脑中常见的宏观、微观和血管变化与神经退行性环境中的变化形成对比。我们还回顾了大脑中随年龄增长而发生的分子变化，例如基因表达的改变、胰岛素/胰岛素样生长因子 1 信号传导功能障碍、翻译后蛋白质修饰、线粒体功能障碍、自噬和钙电导变化。