Linking interneuron-mediated circuit regulation with sleep-dependent plasticity and memory storage in the hippocampus

将中间神经元介导的回路调节与海马体的睡眠依赖性可塑性和记忆存储联系起来

• 批准号: 10700761
• 负责人: SARA J ATON
• 金额: $ 47.02万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-30 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10700761
• 关键词: Linking; interneuron; mediated; circuit; regulation

Project summary: Synaptic plasticity in brain structures like the hippocampus has been hypothesized to underlie an essential brain function - consolidating transient experiences into long-lasting memories. The importance of sleep for promoting long-term memory storage, and the disruptive effect of sleep deprivation on memory, have been appreciated for nearly a century. However, it remains unclear how sleep-associated changes in the activity of specific brain circuits contribute to synaptic plasticity in the hippocampus and other structures. The studies proposed here will test a novel hypothesis – that sleep and sleep loss differentially affect memory consolidation through their differential effects on separate subpopulations of hippocampal interneurons. We will use a simple behavioral paradigm for studying sleep-dependent memory consolidation in mice (contextual fear memory; CFM) in combination with state-targeted pharmacogenetic and optogenetic manipulations of parvalbumin-expressing (PV+) and somatostatin-expressing (SOM+) hippocampal interneurons. In the context of these experimental manipulations, we will measure downstream effects on sleep- associated CFM consolidation, hippocampal network activity, microcircuit-level changes in neuronal structure, and biochemical changes in genetically-defined cell populations. We will first assess the effects of learning itself (contextual fear conditioning; CFC) and subsequent sleep or sleep deprivation (SD) on neuronal morphology using cell type-specific Brainbow labeling, and intracellular processes using cell type-specific translating ribosome affinity purification (TRAP). We will then determine how state-specific manipulations of hippocampal PV+ interneuron activity (which disrupt of rescue sleep-dependent CFM consolidation) affect these sleep- dependent processes. Finally, we will test the hypothesis that SD disrupts CFM consolidation by selectively activating SOM+ interneurons in the hippocampus, leading to suppression of activity in neighboring neurons. We will test whether pharmacogenetic activation of these neurons (mimicking effects of SD) disrupts CFM consolidation in freely-sleeping mice, and whether inhibition of these neurons during SD (mimicking effects of sleep) rescues CFM consolidation. We will then assess the effects of changing SOM+ interneuron activity levels on post-CFC changes in hippocampal network activity patterns, neuronal morphology, and cell biology. Together, these studies will test the necessity and sufficiency of state-dependent activity in defined hippocampal neuron populations for long-term storage of new memories.

项目总结：海马等大脑结构中的突触可塑性已经被假设为