Contributions of Hippocampal Subsystems to Different Aspects of Episodic Memory

人们经常将复杂的日常环境中的经验流组织成情节，这些情节至少包含关于发生了什么、不同物品或事件的位置以及它们发生的顺序的信息。海马体在大脑形成这些情节记忆的过程中起着关键作用。这位研究人员和其他人的研究发现，啮齿类动物会获得“什么”、“在哪里”和“何时”记忆的简化版本；随后的神经行为研究发现，与这些记忆中的每一个相关的海马体网络。这项拟议的实验将确定这些动物是否还表达了人类情节记忆的另外两个关键特征--使用上下文来检索特定的情节，以及一个项目来提示回忆下一个情节--然后定位潜在的网络。初步结果表明，啮齿类动物同时使用这两种操作。对这些功能背后的网络层面操作的描述将使我们能够研究情景记忆对更高阶认知操作的贡献，包括对人类体验至关重要的推理思维。它还可以为计算机化学习系统指明方向，消除目前人工智能版本的已知限制。拟议的工作将使用申请人实验室开发的啮齿动物学习范例的修改形式。这些包括气味序列，即动物与生俱来的兴趣线索。这些协议不需要重复或公开的奖励，因此与人类情节记忆的基本方面一致。这项工作的网络追踪部分将使用化学遗传学技术来瞬时沉默海马体和相关结构中的特定通路。结果将根据一般假设和相关的计算机模型进行评估。除了科学进步，该项目还将为高中生、本科生和研究生提供一个培训、指导和研究活动的环境。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

People routinely organize the flow of experience in complex everyday environments into episodes that minimally contain information about what happened, where different items or events were located, and the order in which they occurred. The hippocampus plays a critical role in the brain’s formation of these episodic memories. Studies by the investigator and others found that rodents acquire simplified versions of ‘what’, ‘where’, and ‘when’ memory; subsequent neurobehavioral investigations identified hippocampal networks associated with each of these. The proposed experiments will determine if the animals also express two other critical features of human episodic memory – using context to retrieve a specific episode and one item to prompt recall of the next -- and then localize the underlying networks. Preliminary results suggest that rodents utilize both of these operations. A description of the network level operations underlying these functions would enable work on episodic memory’s contributions to higher order cognitive operations, including inferential thinking, that are vital to the human experience. It could also point the way to computerized learning systems that obviate known limitations on present versions of artificial intelligence.The proposed work will use modified forms of rodent learning paradigms developed in the applicant’s laboratory. These involve sequences of odors, cues that are of innate interest to the animals. The protocols do not require repetition or overt rewards and thus align with cardinal aspects of human episodic memory. The network-tracing portion of the work will employ chemogenetic techniques for transiently silencing specific pathways within the hippocampus and allied structures. Results will be evaluated with regard to a general hypothesis and associated computer models. In addition to the scientific advances, the project will provide an environment of training, mentoring and research activities for high school, undergraduate and graduate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.