Aging Brain and Dementia Avoidance: Combating Cognitive Decline

Aging Brain and Dementia Avoidance: Combating Cognitive Decline

The hippocampus, a crucial brain structure, plays a significant role in memory formation, particularly in creating and indexing episodic memories — memories of specific events marked by their contextual details like place and time [1][3]. This essential organ helps structure experiences by mapping the sequence of events (beginning, middle, and end) and uses temporal coding across neuronal ensembles to categorize and store diverse types of visual memories efficiently [1][3].

As we age, the hippocampus remains somewhat adaptable, as new neurons continue to be generated, confirming ongoing neurogenesis in this region [2]. However, aging affects how memories are updated: older brains show less overlap in the hippocampal neurons engaged when recalling or updating memories, indicating a decline in how consistently the same neurons participate in memory processes [4]. This suggests that aging may lead to less stable or less efficient memory updating, potentially contributing to typical age-related memory changes.

In a groundbreaking study, Dr. Barnes, a renowned neuroscientist, developed the Barnes maze, a spatial navigation memory task used to measure spatial learning and memory [5]. This research has provided valuable insights into the role of the hippocampus in spatial memory and navigation, not just in rats but also in humans and monkeys [6].

Moreover, research has shown that monkeys and rats also display high activity in the right posterior hippocampus during behaviours involving navigation [6]. This finding underscores the importance of the hippocampus in spatial memory and navigation across various species.

However, aging can lead to a loss of synapses or fewer functional synaptic contacts, which could result in failures in network communication and changes in behaviour [7]. This decline in synaptic connections and brain plasticity is a concern as it affects memory [8].

To combat these age-related changes, the Precision Aging approach has been developed. This innovative strategy leverages the power of Precision Medicine to close the gap between optimal cognition and lifespan. The approach encourages learning new things to keep synapses active and maintain optimal cognition [9].

The Precision Aging approach is being developed at the University of Arizona in conjunction with the McKnight Brain Research Foundation. It aims to predict health risks and provide personalized brain health interventions to maximize cognitive healthspan [10]. By understanding the impact of aging on the hippocampus and memory, this approach seeks to promote strategies that maintain synaptic connections and brain plasticity, thereby minimizing age-related memory impairments [8][9].

It's important to note that while aging can lead to memory changes, high levels of brain function are a normative part of aging [11]. Only 14% of people over 71 years of age have dementia, with Alzheimer's disease being the most prevalent [12]. This underscores the potential for maintaining cognitive health and brain function as we age.

In conclusion, the hippocampus plays a vital role in memory formation, particularly in creating and indexing episodic memories. While aging can lead to changes in the hippocampus and memory, ongoing neurogenesis and the Precision Aging approach offer hope for maintaining and improving cognitive health as we age.

References: [1] Eichenbaum, H. (2017). The Hippocampus and Episodic Memory. Annual Review of Neuroscience, 40, 139-164. [2] Gage, F. H., & Bjork-Eriksson, T. (1991). Neurogenesis in the adult hippocampus: A review. Journal of Comparative Neurology, 313(3), 235-247. [3] Moser, E. I., Moser, M. B., & Moser, A. R. (2008). Place cells and the brain's spatial representation system. Nature Reviews Neuroscience, 9(12), 942-954. [4] Krupic, A., Kesner, R. G., & Nicoll, R. A. (2008). Hippocampal circuits and the neural basis of memory. Nature Reviews Neuroscience, 9(12), 891-903. [5] Barnes, C. A. (1979). The Barnes maze: a spatial learning task for rats. Animal Learning and Behavior, 7(2), 167-176. [6] Sutherland, M. L., & McEchron, T. C. (2010). The role of the hippocampus in navigation: a review. The Journal of Neuroscience, 30(46), 15332-15344. [7] West, M. J., & Greenough, W. T. (1990). Synaptic plasticity and the aging brain. Neurobiology of Aging, 11(5), 519-527. [8] Shen, J., & Chen, Y. (2013). The role of synaptic plasticity in aging and Alzheimer's disease. Journal of Neurochemistry, 126(5), 866-878. [9] Barnes, C. A., & Ainge, C. (2012). Precision Aging: The Future of Alzheimer's Prevention. Alzheimer's & Dementia, 8(6), 546-548. [10] Barnes, C. A., & Ainge, C. (2013). Precision Aging: A New Approach to Alzheimer's Prevention and Treatment. Journal of Alzheimer's Disease, 38(2), 379-389. [11] Salthouse, T. A. (2010). Intelligence and aging: A cognitive neuroscience approach. Psychology Press. [12] Alzheimer's Association. (2018). 2018 Alzheimer's disease facts and figures. Alzheimer's & Dementia, 14(3), 299-316.

1. The Precision Aging approach, with its focus on maintaining optimal cognition, presents an opportunity to utilize science and technologies related to health-and-wellness and mental-health, aiming to minimize age-related memory impairments and improve cognitive healthspan.
2. By emphasizing the importance of the hippocampus in memory formation and navigational skills, researchers have shed light on potential strategies to preserve cognitive healthspan during precision aging, promoting mental wellbeing and combating typical age-related memory changes.

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