Stability and Robustness of Hippocampal Representations of Space

项目总结 大脑如何平衡保存先前知识的需要和不断学习的需要 有新消息吗？稳定性和可塑性之间的ff是生物和艺术所固有的 学习系统受到fiNite资源和能力的限制。海马体是大脑中的一个关键区域 记忆形成和空间学习，可以提供一个强大的实验系统来表征 这个叫ff的交易员。海马体在空间认知中的作用得到了fi和锥体神经元的支持 此区域(放置细胞)中的神经元位于特定环境中的位置(Placefifi)。中国的人口 在一个环境中活跃的细胞被认为形成了一个神经表征或认知图谱 环境。空间学习对生存至关重要，涉及两个相互竞争的约束： 空间必须是塑料的，以便能够快速学习新环境和行为意外情况的变化， 并随着时间的推移保持稳定，以实现熟悉环境的识别、可靠的导航和利用 以前学过的东西。这些相互竞争的约束如何影响Placefffi场随时间的稳定性？这个 海马区空间表征长期稳定性的实验表征 一直具有挑战性，因为它需要在更长的时间段内跟踪多个位置单元的活动 (天到周)。我们建议在大规模电生理学和成像中使用新的方法 以啮齿动物的行为来表征哪些神经元改变了它们的空间调谐以及这些变化是如何依赖的 在行为上。此外，我们将使用录音和电路扰动来表征活动模式 这预示着调谐稳定性的变化。我们的分析将在一个理论的背景下进行 理解海马区表达的可塑性和稳定性之间相互作用的框架。 表征神经表征的进化对于理解神经表征如何 信息是通过大脑回路维持的，以及这种维持是如何在大脑紊乱中受到干扰的。

PROJECT SUMMARY How does the brain balance the need to preserve prior knowledge with the necessity to continuously learn new information? The tradeoff between stability and plasticity is inherent in both biological and artificial learning systems constrained by finite resources and capacity. The hippocampus is a brain region critical for memory formation and spatial learning, which can provide a powerful experimental system for characterizing this tradeoff. The role of the hippocampus in spatial cognition is supported by the finding that pyramidal neurons in this area (place cells) fire in specific locations in an environment (place fields). The population of place cells active in an environment is believed to form a neural representation or cognitive map of that environment. Spatial learning is critical for survival and involves two competing constraints: representations of space must be plastic to enable fast learning of new environments and changes in behavioral contingencies, and stable over time to enable recognition of familiar environments, reliable navigation, and leveraging of previous learning. How do these competing constraints affect the stability of place fields across time? The experimental characterization of the long-term stability of spatial representations in the hippocampus has been challenging as it requires tracking the activity of multiple place cells across extended periods of time (days to weeks). We propose to use novel approaches in large-scale electrophysiology and imaging in behaving rodents to characterize which neurons change their spatial tuning and how these changes depend on behavior. Furthermore, we will use recordings and circuit perturbations to characterize the activity patterns that predict changes in tuning stability. Our analysis will be carried out in the context of a theoretical framework for understanding the interplay between plasticity and stability of hippocampal representations. Characterizing the evolution of neural representations is of fundamental importance in understanding how information is maintained across brain circuits and how such maintenance is perturbed in brain disorders.