The present experiments compared the effects of aging on learning several hippocampus- and striatum-sensitive tasks in young (3-4 month) and old (24-28 month) male Fischer-344 rats. Across three sets of tasks, aging was accompanied not only by deficits on hippocampal tasks but also by maintained or even enhanced abilities on striatal tasks. On two novel object recognition tasks, rats showed impaired performance on a hippocampal object location task but enhanced performance on a striatal object replacement task. On a dual solution task, young rats predominately used hippocampal solutions and old rats used striatal solutions. In addition, on two maze tasks optimally solved using either hippocampus-sensitive place or striatum-sensitive response strategies, relative to young rats, old rats had impaired learning on the place version but equivalent learning on the response version. Because glucose treatments can reverse deficits in learning and memory across many tasks and contexts, levels of available glucose in the brain may have particular importance in cognitive aging observed across tasks and memory systems. During place learning, training-related rises in extracellular glucose levels were attenuated in the hippocampus of old rats compared to young rats. In contrast, glucose levels in the striatum increased comparably in young and old rats trained on either the place or response task. These extracellular brain glucose responses to training paralleled the impairment in hippocampus-sensitive learning and the sparing of striatum-sensitive learning seen as rats age, suggesting a link between age-related changes in learning and metabolic substrate availability in these brain regions.

中文翻译：

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内存系统的老化是不相等的。

本实验比较了衰老对年轻（3-4 个月）和老年（24-28 个月）雄性 Fischer-344 大鼠学习若干海马和纹状体敏感任务的影响。在三组任务中，衰老不仅伴随着海马任务的缺陷，而且还伴随着纹状体任务的维持甚至增强能力。在两项新的物体识别任务中，大鼠在海马物体定位任务中表现出受损的表现，但在纹状体物体替换任务中表现出增强的表现。在双重解决方案任务中，年轻大鼠主要使用海马溶液，而老年大鼠主要使用纹状体溶液。此外，相对于幼鼠，在使用海马敏感位置或纹状体敏感反应策略最佳解决的两个迷宫任务中，老老鼠在地方版本上的学习受损，但在响应版本上的学习相当。由于葡萄糖治疗可以逆转许多任务和环境中的学习和记忆缺陷，大脑中可用葡萄糖水平可能对跨任务和记忆系统观察到的认知老化具有特别重要的意义。在地方学习期间，与年轻大鼠相比，老年大鼠海马中与训练相关的细胞外葡萄糖水平升高减弱。相比之下，在接受地点或反应任务训练的年轻和老年大鼠中，纹状体中的葡萄糖水平相对增加。这些细胞外脑葡萄糖对训练的反应与海马敏感学习的损害和纹状体敏感学习随着大鼠年龄增长而受到的损害相似，