Exercise recovers cholinergic dysfunction through neurotrophin modulation

描述（由申请人提供）：与正常衰老和神经退行性疾病相关的认知和记忆障碍正在成为我国最大的健康问题之一。治疗性运动已经成为一种非侵入性的技术，以改善健康和神经受损人群的学习，记忆和认知。我们提出了一个新的观点，即运动诱导的学习和记忆改善是由两个因素驱动的：第一，脑源性神经营养因子（BDNF）的急性上升增强记忆;第二，神经营养因子的长期增加导致基底前脑胆碱能神经元的选择性拯救，这些神经元共表达巢蛋白，最终产生突触功效的增加。这些增强增强了隔海马回路内活动相关的乙酰胆碱（ACh）释放，这就是运动后学习延迟改善的原因。这项工作将通过为一种新的 运动如何通过胆碱能系统的调节改善认知功能的机械论。在这个建议中，我们将确定是否持续运动诱导的神经营养因子，特别是神经生长因子（NGF）的释放，将拯救一个选定的人口胆碱能前脑神经元，共同表达巢蛋白从一个营养不良的静态产生的硫胺素缺乏症在啮齿动物模型的健忘症（AIM 1）。此外，我们将证明运动促进的BDNF和ACh的活动依赖性释放的改善是时间依赖性的，并且独特地驱动不同认知过程的增强。此外，运动激活的TrkA或TrkB受体选择性上调关键的突触蛋白参与不同的时间分布的神经化学释放和行为改善（AIM 2）。开发认知/记忆障碍的行为和药理学治疗干预措施需要更好地了解病理性大脑如何与健康大脑不同地反应和适应。需要这些关键的临床前信息来改善对认知功能恢复有效的治疗策略的开发。

DESCRIPTION (provided by applicant): Cognitive and memory impairments associated with normal aging and neurodegenerative disease are emerging as one of our nation's greatest health concerns. Therapeutic exercise has emerged as a non- invasive technique to improve learning, memory and cognition in both healthy and neurologically compromised populations. We posit a novel position that exercise-induced improvements in learning and memory are driven by two factors: First, acute rises in brain derived neurotrophic factor (BDNF) enhance memory; and second, the protracted increases in neurotrophins lead to a selective rescue of basal forebrain cholinergic neurons that co-express nestin that ultimately produces an increase in synaptic efficacy. These enhancements intensify activity-related acetylcholine (ACh) release within the septohippocampal circuit and this is what produces the delayed improvements in learning after exercise. This work will advance the field by providing proof of principle for a new mechanistic theory for how exercise can lead to improved cognitive functioning based on the modulation of the cholinergic system. In this proposal we will determine whether sustained exercise-induced release of neurotrophins, in particular nerve growth factor (NGF), will rescue a select population of cholinergic forebrain neurons that co-express nestin from a hypotrophic quiescent state produced by thiamine deficiency in a rodent model of amnesia (AIM 1). In addition, we will demonstrate the exercise-facilitated improvements in activity-dependent release of BDNF and ACh are time-dependent and uniquely drive the enhancement of different cognitive processes. Moreover, exercise activation of TrkA or TrkB receptors selectively upregulate critical synaptic proteins involved in the distinct temporal profile of neurochemical release and behavioral improvement (AIM 2). Developing both behavioral and pharmacological therapeutic interventions for cognitive/memory disorders requires a greater understanding of how the pathological brain reacts and adapts differently from the healthy brain. Such critical pre-clinical information is needed to improve the development of therapeutic strategies that are effective for the recovery of cognitive functions.