Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, Scotland, UK.
Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, Scotland, UK; Centre for Cognitive Ageing and Cognitive Epidemiology, The University of Edinburgh, Edinburgh, Scotland, UK.
Neurobiol Aging. 2018 Jul;67:31-41. doi: 10.1016/j.neurobiolaging.2018.02.023. Epub 2018 Mar 10.
Decline in cognitive functions, including hippocampus-dependent spatial memory, is commonly observed at a later stage of aging (e.g., >20 months old in rodents) and typically studied after a discrete learning event. How normal aging, particularly at an early stage, affects the modulatory aspect of memory persistence is underinvestigated. Previous studies in young animals show that weak, fading memories can last longer if a modulating event, such as spatial novelty, is introduced around memory encoding. This is known as behavioral tagging and capture (BTC). Here, we investigated how early aging (10-13 months old) affects BTC in an appetitive delayed-matching-to-place task. We trained rats when they were young and middle aged and found that novelty facilitated long-term memory persistence in young but not in middle-aged rats. However, re-exposure to the encoded environment after learning improved memory persistence in middle-aged rats. BTC, combined with memory reactivation, facilitated memory persistence through reconsolidation. Our results point toward a weakened tagging and capture mechanism before reduction of plasticity-related proteins at an early stage of aging.
认知功能下降，包括海马依赖的空间记忆，通常在老年后期（例如，在啮齿动物中 >20 个月）观察到，通常在离散的学习事件后进行研究。正常衰老，特别是在早期阶段，如何影响记忆持久性的调节方面还研究不足。以前在年轻动物中的研究表明，如果引入调节事件，例如空间新颖性，围绕记忆编码，可以使较弱、逐渐消失的记忆持续更长时间。这被称为行为标记和捕获（BTC）。在这里，我们研究了早期衰老（10-13 个月大）如何影响在奖赏性延迟匹配位置任务中的 BTC。我们在大鼠年轻时和中年时进行训练，发现新颖性促进了年轻大鼠但不促进中年大鼠的长期记忆持久性。然而，学习后重新暴露于编码环境改善了中年大鼠的记忆持久性。BTC 与记忆再激活相结合，通过再巩固促进了记忆持久性。我们的结果表明，在衰老早期减少与可塑性相关的蛋白质之前，标记和捕获机制减弱。
