Aging is associated with specific impairments of learning and memory, some of which are similar to those caused by hippocampal damage. Studies of the effects of aging on hippocampal anatomy, physiology, plasticity, and network dynamics may lead to a better understanding of age-related cognitive deficits. Anatomical and electrophysiological studies indicate that the hippocampus of the aged rat sustains a loss of synapses in the dentate gyrus, a loss of functional synapses in area CA1, a decrease in the NMDA-receptor-mediated response at perforant path synapses onto dentate gyrus granule cells, and an alteration of Ca(2+) regulation in area CA1. These changes may contribute to the observed age-related impairments of synaptic plasticity, which include deficits in the induction and maintenance of long-term potentiation (LTP) and lower thresholds for depotentiation and long-term depression (LTD). This shift in the balance of LTP and LTD could, in turn, impair the encoding of memories and enhance the erasure of memories, and therefore contribute to cognitive deficits experienced by many aged mammals. Altered synaptic plasticity may also change the dynamic interactions among cells in hippocampal networks, causing deficits in the storage and retrieval of information about the spatial organization of the environment. Further studies of the aged hippocampus will not only lead to treatments for age-related cognitive impairments, but may also clarify the mechanisms of learning in adult mammals.

中文翻译：

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衰老对海马功能的影响：可塑性，网络动力学和认知。

衰老与特定的学习和记忆障碍有关，其中一些与海马损伤引起的相似。关于衰老对海马解剖学，生理学，可塑性和网络动力学的影响的研究可能会导致对与年龄有关的认知缺陷的更好的理解。解剖和电生理研究表明，成年大鼠海马在齿状回中维持突触丧失，在CA1区丧失功能性突触，在穿孔通路突触到齿状回颗粒细胞上NMDA受体介导的反应减少。 ，并且改变了CA1区域中Ca（2+）的调控。这些变化可能导致与年龄相关的突触可塑性受损，其中包括长期增强（LTP）的诱导和维持方面的缺陷，以及去势和长期抑郁的阈值较低（LTD）。LTP和LTD平衡的这种变化反过来可能会损害记忆的编码并增强记忆的擦除，因此导致许多年老哺乳动物经历的认知缺陷。改变的突触可塑性也可能改变海马网络中细胞之间的动态相互作用，从而导致有关环境空间组织的信息的存储和检索不足。对老年海马的进一步研究不仅将导致与年龄有关的认知障碍的治疗，而且还可能阐明成年哺乳动物的学习机制。反过来，会损害记忆的编码并增强记忆的擦除，因此导致许多年老哺乳动物经历的认知缺陷。改变的突触可塑性也可能改变海马网络中细胞之间的动态相互作用，从而导致有关环境空间组织的信息的存储和检索不足。对老年海马的进一步研究不仅将导致与年龄有关的认知障碍的治疗，而且还可能阐明成年哺乳动物的学习机制。反过来，会损害记忆的编码并增强记忆的擦除，因此导致许多年老哺乳动物经历的认知缺陷。改变的突触可塑性也可能改变海马网络中细胞之间的动态相互作用，导致有关环境空间组织的信息的存储和检索不足。对老年海马的进一步研究不仅将导致与年龄有关的认知障碍的治疗，而且还可能阐明成年哺乳动物的学习机制。导致存储和检索有关环境空间组织的信息不足。对老年海马的进一步研究不仅将导致与年龄有关的认知障碍的治疗，而且还可能阐明成年哺乳动物的学习机制。导致存储和检索有关环境空间组织的信息不足。对老年海马的进一步研究不仅将导致与年龄有关的认知障碍的治疗，而且还可能阐明成年哺乳动物的学习机制。