Hippocampal Neural Correlates of Memory Enhancement Via Theta-Rhythmic Human Brain Stimulation Via Simultaneous TMS/fMRI

项目摘要 在θ波段频率（4-8-Hz）振荡的神经活动被认为提供了一个时间框架， 海马体内的情景记忆编码，并协调记忆相关的处理， 分布式大脑皮层网络（HCN）。然而，以前的尝试，以表征功能 HCN θ-带活动在人类中的作用由于依赖于相关的神经活动而受到限制 记录不能产生强因果推论的方法。在以前的研究中，我的实验室 证明了θ脉冲经颅磁刺激应用于HCN的皮质节点， 相对于对照刺激，HCN记忆功能产生持久变化。这个项目的总体目标是 建议的项目是建立在这些以前的发现，通过获得神经相关的影响θ-突发 刺激HCN记忆加工。这将为theta在人类HCN中的作用提供因果检验 记忆处理为了实现这一目标，我们将使用一种新的方法，即网络靶向θ- 在执行记忆任务期间，脉冲串刺激与功能磁共振成像神经成像同时传递。我们 假设传递到HCN皮质节点的θ爆发刺激将调节海马 记忆处理这种网络靶向θ脉冲串刺激的效果将与两种方法进行比较。 控制条件，一个涉及靶向不同的网络（网络控制），一个涉及刺激 以非θ脉冲串频率（频率控制）。此外，记忆任务将使我们能够区分 θ-爆发刺激对依赖于大脑的记忆处理的影响与对照任务相比， 不涉及记忆处理。我们假设HCN靶向θ爆发刺激会导致 在记忆处理过程中选择性地增加海马体的活动，并将增强记忆的形成 相对于各种控制条件。这项建议提供了复杂的多方面的培训机会， 方法实验设计和基于任务的fMRI分析。研究结果将为HCN记忆理论提供信息 处理.此外，破坏HCN θ振荡与记忆障碍有关， 因此，这些发现可能会激发大脑刺激治疗记忆障碍的新应用。

PROJECT SUMMARY ABSTRACT Neural activity oscillating at theta-band frequencies (4-8-Hz) is thought to provide a temporal framework for episodic memory encoding within the hippocampus and to coordinate memory-related processing across a distributed hippocampal-cortical network (HCN). However, previous attempts to characterize the functional role of HCN theta-band activity in humans have been limited in their reliance on correlational neural activity recording methods that do not yield strong causal inferences. In previous research, my laboratory has demonstrated that theta-burst transcranial magnetic stimulation applied to cortical nodes of the HCN generates lasting changes in HCN memory function, relative to control stimulation. The overall goal of this proposed project is build on these previous findings by obtaining neural correlates of the impact of theta-burst stimulation on HCN memory processing. This will provide a causal test of the role of theta in human HCN memory processing. To accomplish this goal, we will use a novel method whereby network-targeted theta- burst stimulation is delivered concurrently with fMRI neuroimaging during performance of a memory task. We hypothesize that theta-burst stimulation delivered to a cortical node of the HCN will modulate hippocampal memory processing. The effects of this network-targeted theta-burst stimulation will be compared to two control conditions, one involving targeting a different network (network control) and one involving stimulation at a non-theta-burst frequency (frequency control). Furthermore, the memory task will allow us to distinguish effects of theta-burst stimulation on hippocampal-dependent memory processing versus on a control task that does not involve memory processing. We hypothesize that HCN-targeted theta-burst stimulation will cause greater hippocampal activity selectively during memory processing and will enhance memory formation relative to the various control conditions. This proposal offers training opportunities in sophisticated multi- method experimental designs and task-based fMRI analyses. Findings will inform theories of HCN memory processing. Furthermore, disrupted HCN theta oscillations have been implicated in memory disorders, and findings could therefore motivate new therapeutic applications of brain stimulation for memory impairments.