AGING, ATTENTION AND THE BASALOCORTICAL PATHWAY

选择性注意力障碍和分散注意力障碍是最严重的两种 与衰老相关的可靠的认知缺陷。信息 关于涉及的神经生物学机制和神经回路 在过去的十年里，人们的注意力开始积累起来。然而， 人们对这些机制和电路是如何 随着年龄的增长而改变。拟议中的研究检查了老年大鼠是否有 选择性和分散注意力受损，如老年人所表现的 人类。此外，基底前脑的增龄性变化 前额叶皮质的通路进行了研究。这些大脑区域是 已知对年轻人的选择性和分散注意力很重要 成年人。最后，注意障碍和注意障碍之间的关系 相关分析探讨了解剖结构的变化。这个 假说是老年人的选择性注意力和分散注意力受损。 大鼠由于基底前脑神经元的退化而投射到 额叶皮质。老年和年轻成年大鼠分3个版本进行测试 两项选择的反应时间任务，以评估选择性和区分 请注意。所检查的条件是单一任务，它衡量 在单项2项选择辨别上的表现，选择哪项任务 使用以下参数测量单个二选项歧视的性能 分心物，以及衡量两个人的表现的双重任务 同时进行二项选择辨别。之间的性能差异 选定的任务条件和单个任务条件提供了一种选择性的度量 注意力能力。双任务和单任务之间的性能差异 条件提供了一种分散注意力能力的衡量标准。之后 行为测试，大脑被处理以进行解剖分析。基本的 投射到额叶皮质的前脑神经元被标记为 逆行示踪剂。这些神经元被细分为胆碱能和 含钙结合蛋白的神经元，因为这些神经元代表种群 这可能会随着年龄的增长而退化。对这些问题的定量分析 神经元群体是用体视学制作的。与年龄相关的变化 神经元群体与注意力障碍相关。这些 研究很重要，因为它们开始识别神经回路 这可能是与年龄相关的注意力障碍和 提供对开发有针对性的治疗方法至关重要的信息 防止与衰老相关的认知能力下降。

Impairments of selective and divided attention are two of the most reliable cognitive deficits associated with aging. Information concerning the neurobiological mechanisms and neural circuits involved in attention has started to accumulate in the past decade. However, relatively little is known about how these mechanisms and circuits change with age. The proposed studies examine whether aged rats have impaired selective and divided attention, as demonstrated in aged humans. Furthermore, the age-related changes in the basal forebrain pathway to the frontal cortex are examined. These brain regions are known to be important for selective and divided attention in young adults. Finally, the relationship between attentional impairments and anatomical changes are explored by correlational analyses. The hypothesis is that selective and divided attention are impaired in aged rats due to the degeneration of basal forebrain neurons that project to the frontal cortex. Aged and young adult rats are tested in 3 versions of a two-choice reaction time task to assess selective and divided attention. The conditions examined are single task which measures performance on a single 2-choice discrimination, selected task which measures performance on a single 2-choice discrimination with distractors, and dual task which measures performance on two simultaneous 2-choice discriminations. Performance differences between selected and single task conditions provide a measure of selective attention ability. Performance differences between dual and single task conditions provide a measure of divide attention ability. After behavioral testing, brains are processed for anatomical analyses. Basal forebrain neurons that project to the frontal cortex are labeled with retrograde tracers. These neurons are subdivided into cholinergic and calbindin-containing neurons because these neurons represent populations that may degenerate during aging. Quantitative analyses of these neuronal populations are made using stereology. Age-related changes in neuronal populations are correlated with attentional impairments. These studies are important because they start to identify the neural circuits that may be responsible for the age-related impairments of attention and provide information that is essential for developing treatments aimed at preventing the cognitive decline associated with aging.