Recovering amnestic memories from the repeat head impact brain

项目概要（摘要） 充满头部撞击（HI）的运动生涯使运动员容易出现记忆障碍， 包括阿尔茨海默病在内的痴呆症的危险因素。虽然蛋白质病显然与大脑 在这些疾病的晚期功能障碍，记忆问题也是一种常见的症状， 报告了早期疾病的病例-甚至那些没有神经退行性疾病的病例 病理为了了解HI引起的慢性记忆障碍的本质，我们专注于 在暴露于高频率的非损伤性辐射后大脑中发生的生理变化 HI（HFHI），并将我们的结果与单一严重单一TBI进行比较。我们的初步数据显示， 将小鼠暴露于HFHI引起兴奋性突触的适应性反应。这些适应发生在 以牺牲正常的大脑功能为代价，在学习和 记忆这种突触阻尼是永久性的，不会自发逆转。本提案中 我们的目标是确定我们是否可以逆转受伤大脑中的慢性突触功能障碍，并回忆起一个 遗忘的记忆 在这个建议中，我们将测试HFHI破坏突触内传递的假设。 海马体的记忆回路，而记忆印记神经元的激活可以覆盖这些记忆回路。 认知缺陷和唤醒被遗忘的记忆 这些数据将使我们能够测试是否有可能通过针对 不同类型TBI中的突触。这将对数百万生活在 头部撞击后认知和行为功能障碍，可以利用它来减少 每年发展为阿尔茨海默病的TBI患者人数。

PROJECT SUMMARY (ABSTRACT) An athletic career filled with head impacts (HI) predisposes athletes to memory impairments and is a risk factor for dementias including Alzheimer’s disease. While proteinopathy is clearly linked to brain dysfunction in the late stages of these disease, memory problems are also a common symptom in reported cases with early-stage disease – and even those cases with no neurodegenerative disease pathology. To understand the nature of the chronic memory impairments caused by HI, we are focused on the physiological changes that occur in the brain after exposure to a high frequency of non-damaging HI (HFHI), and comparing our results to a single severe single TBI. Our preliminary data shows that exposing mice to HFHI causes an adaptive response in excitatory synapses. These adaptations occur at the cost of normal brain function, with widespread and prolonged impairments in learning and memory. This synaptic dampening is permanent, and does not spontaneously reverse. In this proposal we aim to determine if we can reverse chronic synaptic dysfunction in the injured brain, and recall a forgotten memory. In this proposal we will test the hypothesis that HFHI disrupts synaptic transmission within the memory circuits of the hippocampus, and that activation of engram neurons can override these cognitive deficits and reanimate a forgotten memory. These data will allow us to test if it will be possible to treat cognitive impairments by targeting the synapse in different types of TBI. This will have profound implications for the millions of people living with cognitive and behavioral dysfunction after head impact, and could be harnessed to reduce the number of TBI patients that progress to develop Alzheimer’s disease each year.