Imaging of Hippocampal Activity Across Sleep/Wake and Disease States

睡眠/清醒和疾病状态下海马活动的成像

• 批准号: 8916842
• 负责人: Thomas S Kilduff
• 金额: $ 25万
• 依托单位: SRI INTERNATIONAL
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8916842
• 关键词: Address; Algorithms; Animals; Arousal; Behavioral; Biological Markers; Brain; Brain region; Calcium; Cell Count; Cells; Chronic; Cognitive; Computer software; Custom; Disease; Disease Progression; Dorsal; Electroencephalography; Emotional; Event; Frequencies; Functional Imaging; Head; Health; Hippocampus (Brain); Huntington Disease; Image; Image Analysis; Individual; Interneurons; Lead; Learning; Longitudinal Studies; Measurement; Measures; Memory; Methodology; Monitor; Mus; Neurons; Paper; Preparation; Publishing; Pyramidal Cells; REM Sleep; Recording of previous events; Recovery; Reporting; Resolution; Role; Signal Transduction; Sleep; Sleep Deprivation; Speed; Structure; Techniques; Technology; Time; Wakefulness; Wireless Technology; behavioral study; calcium indicator; cranium; data acquisition; extracellular; fluorescence imaging; fluorescence microscope; imaging system; innovative technologies; insight; millisecond; motor impairment; mouse model; new technology; non rapid eye movement; novel; pressure; rapid eye movement; relating to nervous system; research study; response; telemetering

DESCRIPTION (provided by applicant): EEG power in the theta frequency range (6-9 Hz), particularly during waking and REM sleep, is believed to primarily be due to synchronous firing of hippocampal pyramidal cells. To date, studies supporting this hypothesis have relied on extracellular unit recordings where a relatively small number of cells are monitored and the activity of individual cells can only be followed for short periods of time. Here, we will provide n unprecedented network level view of neural activity in the hippocampus across arousal states by monitoring the activity of hundreds of individually identifiable cells over weeks to months. We will combine telemetric recording of EEG and EMG activity with an exciting new technology that, when used in conjunction with genetically-encoded fluorescent calcium indicators (e.g., GCaMP5 and 6), enables imaging the activity of hundreds of neurons simultaneously from a local brain region in unanesthetized, freely-moving animals. The Inscopix nVista HD imaging system is comprised of a miniature (<2 g) fluorescence microscope that can be borne on the skull of a mouse, software that enables high-speed imaging (20-100 Hz) over a field of view up to ~0.5 mm2, and microendoscopes that allow imaging with micron-scale resolution in subcortical brain structures. Because of the rich history of behavioral studies conducted in the hippocampus and its laminar organization, this region is the ideal neural structure in which to utilize this technology to obtain novel insights into neural activity across arousal states. First,we will determine the activity of localized networks within CA1 across arousal states and during conditions when homeostatic sleep pressure can be expected to differ, such as early in the "lights on" period vs. early in the dark period and in response to sleep deprivation and subsequent recovery sleep. Concurrent measurement of the activity of hundreds of cells in conjunction with the EEG will enable us to not only follow the activity of individual cells across sleep and wakefulness, but also to evaluate synchrony within the local network with respect to EEG frequencies and specific EEG events. Having defined the parameters of the hippocampal network in wildtype mice, we will then determine the activity of local networks within CA1 in a mouse model of Huntington's disease (HD). We have recently characterized changes in sleep and wakefulness and in the EEG of the R6/2 mouse model of HD and found both tremendously increased power in the theta range and slowing of the theta peak frequency (TPF) as disease progresses. Using theta power and TPF as biomarkers, we will exploit the power of the Inscopix technology to enable long-term recordings of identified neurons to determine how the hippocampal network is reorganized as disease progresses in R6/2 mice. The ability to observe calcium dynamics of hundreds of cells while simultaneously recording EEG in freely-behaving mice may lead to new insights into the role of the hippocampus in behavioral states and the network changes that occur in the hippocampus in HD.

描述（由申请人提供）：theta频率范围内的EEG功率（6-9 Hz），尤其是在醒来和REM睡眠期间，主要是由于海马锥体细胞的同步射击。迄今为止，支持该假设的研究取决于细胞外单位记录，在这些记录中，监测相对较少的细胞，并且只能在短时间内遵循单个细胞的活性。在这里，我们将通过在数周到几个月内监测数百个单独识别的细胞的活性，从而提供跨唤醒状态的海马神经活动的前所未有的网络水平。我们将将EEG和EMG活性的遥测记录与令人兴奋的新技术结合在一起，当与遗传编码的荧光钙指标（例如GCAMP5和6）结合使用时，启用了同时在未经干预的，自由化的，自由化的动物的地方区域的数百个神经元的活性。 The Inscopix nVista HD imaging system is comprised of a miniature (<2 g) fluorescence microscope that can be borne on the skull of a mouse, software that enables high-speed imaging (20-100 Hz) over a field of view up to ~0.5 mm2, and microendoscopes that allow imaging with micron-scale resolution in subcortical brain structures.由于在海马及其层流组织中进行的行为研究的悠久历史，该地区是利用这项技术来获得对整个唤醒状态神经活动的新见解的理想神经结构。首先，我们将确定在唤醒状态下CA1内的局部网络的活性，以及​​在预期体内睡眠压力有所不同的情况下，例如在黑暗时期的“灯光上”与“灯光”早期的早期以及对睡眠剥夺以及随后的恢复睡眠的反应。同时测量数百个细胞与脑电图结合的活性将使我们不仅能够遵循单个细胞在睡眠和清醒之间的活性，还可以评估相对于脑电图频率和特定的脑电图事件，可以评估局部网络中的同步。在定义了野生型小鼠中海马网络的参数之后，我们将在亨廷顿氏病小鼠模型（HD）中确定CA1中局部网络的活性。我们最近表征了睡眠和清醒的变化以及HD的R6/2小鼠模型的脑电图，发现随着疾病的进展，Theta峰频率（TPF）的theta峰频率（TPF）的减速都大大提高了功率。我们将使用Theta功率和TPF作为生物标志物，我们将利用Inscopix技术的力量来启用已识别神经元的长期记录，以确定随着R6/2小鼠疾病的发展，如何重新组织海马网络。观察数百个细胞的钙动力学的能力，同时记录在自由行为的小鼠中的脑电图，可能会导致对海马在行为状态中的作用的新见解，以及在HD中发生的Hippocampus中发生的网络变化。