Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Blk MD9, 2 Medical Drive, Singapore 117597, Singapore; Life Sciences Institute, Neurobiology/Aging Program, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore.
Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Blk MD9, 2 Medical Drive, Singapore 117597, Singapore; Life Sciences Institute, Neurobiology/Aging Program, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore.
Ageing Res Rev. 2017 May;35:22-35. doi: 10.1016/j.arr.2016.12.008. Epub 2017 Jan 5.
Aging is accompanied by a general decline in the physiological functions of the body with the deteriorating organ systems. Brain is no exception to this and deficits in cognitive functions are quite common in advanced aging. Though a variety of age-related alterations are observed in the structure and function throughout the brain, certain regions show selective vulnerability. Medial temporal lobe, especially the hippocampus, is one such preferentially vulnerable region and is a crucial structure involved in the learning and long-term memory functions. Hippocampal synaptic plasticity, such as long-term potentiation (LTP) and depression (LTD), are candidate cellular correlates of learning and memory and alterations in these properties have been well documented in aging. A related phenomenon called synaptic tagging and capture (STC) has been proposed as a mechanism for cellular memory consolidation and to account for temporal association of memories. Mounting evidences from behavioral settings suggest that STC could be a physiological phenomenon. In this article, we review the recent data concerning STC and provide a framework for how alterations in STC-related mechanisms could contribute to the age-associated memory impairments. The enormity of impairment in learning and memory functions demands an understanding of age-associated memory deficits at the fundamental level given its impact in the everyday tasks, thereby in the quality of life. Such an understanding is also crucial for designing interventions and preventive measures for successful brain aging.
衰老是伴随着身体生理机能的全面下降，器官系统逐渐恶化。大脑也不例外，认知功能的衰退在高龄人群中很常见。尽管大脑的结构和功能在各个方面都发生了各种与年龄相关的改变，但某些区域表现出选择性易损性。内侧颞叶，特别是海马体，是这样一个易损区域，是参与学习和长期记忆功能的关键结构。海马体突触可塑性，如长时程增强（LTP）和长时程抑制（LTD），是学习和记忆的细胞相关物，这些特性的改变在衰老过程中得到了很好的记录。一种称为突触标记和捕获（STC）的相关现象被提出作为细胞记忆巩固的机制，并解释记忆的时间关联。来自行为环境的越来越多的证据表明，STC 可能是一种生理现象。在本文中，我们回顾了最近关于 STC 的数据，并提供了一个框架，说明 STC 相关机制的改变如何导致与年龄相关的记忆损伤。学习和记忆功能的严重损伤要求从根本上理解与年龄相关的记忆缺陷，因为它会影响日常生活任务，从而影响生活质量。这种理解对于设计成功的大脑衰老的干预措施和预防措施也至关重要。
