RUI: Perceptual and Mnemonic Functions of the Perirhinal Cortex in Stimulus Representation

所有的动物都有形成记忆的能力。在哺乳动物中，海马体记忆系统是大脑结构的集合体，它们共同发挥作用，支持记忆的形成。在这样做的过程中，这个记忆系统将人、物品和地点联系在一起，形成所谓的情节记忆。情节记忆为物种提供了记忆重要信息的能力，这些信息增加了生存的可能性，例如确保长期的食物来源。在这个例子中，动物必须记住“什么”是储存的，“在哪里”储存的，以及“何时”储存的，以便在食物变质之前取回食物，并避免在这个过程中生病。在海马体记忆系统中，一种被称为周围皮质的结构的主要作用是提供“什么”信息的表示(例如，储存了什么食物)。除了在情景记忆中的作用外，周边皮质似乎也参与了复杂的刺激表征；然而，周边皮质如何以及在什么情况下参与刺激表征目前仍存在争议。这个项目评估了大脑周围皮质在呈现物品信息时如何以知觉特有的方式与记忆特有的方式发挥作用。此外，该项目还研究了大脑周围皮质在刺激表征中的作用是否涉及到与海马体记忆系统之外的结构的联系。这些结果将为深入了解海马区周围皮质对刺激表征的贡献，以及它如何在海马体记忆系统中改变或补充其在情景记忆中的既定角色提供重要的洞察。该研究计划的所有组成部分都为加州州立大学萨克拉门托分校的学生提供培训机会，该大学是一所少数族裔服务机构，主要是本科生。此外，外展活动为学生提供了在社区中提高STEM意识的机会。目前，关于周围皮质如何在刺激表征中发挥作用，以及这一功能是否独立于其在海马体记忆系统中的助记作用存在争议。这个项目使用联想学习范式(巴甫洛夫恐惧条件作用)，结合创新的失活方法，设计者受体被设计者药物独家激活，以及交叉损伤技术来评估周边皮质在刺激表征中的功能作用。具体地说，利用实验室大鼠作为模型系统，该项目的目标是：1)检查需要周围皮质来进行刺激表征的刺激的特征；2)确定周围皮质在刺激表征中的作用是知觉的、助记性的还是两者的组合；以及3)确定在刺激表征中，周围皮质是否依赖于与海马体记忆系统之外的结构的直接联系。该研究项目为加州州立大学萨克拉门托分校的学生提供了广泛的培训机会，该大学是一所少数族裔服务的大学，主要是本科生。此外，社区推广活动包括让小学女生接触科学，促进全大学的大脑意识，并向当地社区展示研究成果，为学生提供在更广泛的社区提高STEM意识的机会。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。

All animals possess the ability to form memories. In mammals, the hippocampal memory system is a conglomerate of brain structures that function together to support memory formation. In doing so, this memory system associates, or binds together, people, items, and places into what are known as episodic memories. Episodic memories afford species the ability to remember vital information that increases the likelihood of survival, such as securing long-term food sources. In this example, the animal must remember "what" was stored, "where" it was stored, and "when" it was stored to retrieve the food before it spoils and avoid illness in the process. Within the hippocampal memory system, the predominant role of one structure, called the perirhinal cortex, is to supply a representation of "what" information (e.g., what food item was stored). The perirhinal cortex also appears to be involved in complex stimulus representations outside of its role in episodic memory; however, how and under which circumstances the perirhinal cortex is involved in stimulus representation is currently under debate. This project assesses how the perirhinal cortex functions in a perceptual-specific versus a memory-specific manner in its representation of item information. In addition, the project examines whether the role of the perirhinal cortex in stimulus representation involves connections with structures outside of the hippocampal memory system. Results will furnish significant insight into the contributions of the perirhinal cortex to stimulus representation and how it may differ or complement its well-established role in episodic memory within the hippocampal memory system. All components of the research program provide training opportunities to students at California State University-Sacramento, a minority serving and primarily undergraduate institution. Additionally, outreach events provide students with opportunities to increase STEM-awareness in the community.Currently, it is debated how the perirhinal cortex may function in stimulus representation, and if this function is independent from its mnemonic role within the hippocampal memory system. This project uses an associative learning paradigm (Pavlovian fear conditioning) in combination with an innovative inactivation method, Designer Receptors Exclusively Activated by Designer Drugs, and cross-lesion techniques to evaluate the functional role of the perirhinal cortex in stimulus representation. Specifically, using the laboratory rat as a model system the project aims to: 1) examine the characteristics of stimuli that require the perirhinal cortex for stimulus representation; 2) determine whether the role of perirhinal cortex in stimulus representation is perceptual, mnemonic or a combination; and 3) determine whether in stimulus representation the perirhinal cortex relies on direct connections with structures outside of the hippocampal memory system. The research project provides extensive training opportunities to students at California State University-Sacramento, which is a minority serving and primarily undergraduate institution. Further, community outreach, which includes events that expose elementary school girls to science, promote university-wide brain awareness and present research findings to the local community, provide students with opportunities to increase STEM-awareness in the broader community.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.