The Role of Long-Range Inhibitory Neurons in Cortical Circuits

项目摘要 当具有不同行为状态的动物的行为状态发生变化时，皮层活动发生显著变化，例如 就像睡眠和清醒一样，对大脑皮层的处理有着深远的影响。负责感知行为状态的电路 并且修改皮层活动以产生皮层状态仍然是未知的。然而，抑制性神经元（INs）已经被 最近卷入了这个角色。有趣的是，行为状态的失调和IN的破坏都是标志性的 严重的神经精神疾病在这里，我认为皮层中一种特殊的抑制性神经元亚型起着作用， 低频振荡的产生，这是多种皮质状态的标志。我建议远程抑制 皮层的神经元在低频振荡的产生中起着至关重要的作用。 长程抑制神经元在形态和功能上都与皮层中的其他细胞类型有很大的不同。 基因表达。虽然皮层中的其他IN在局部投射，但长程抑制神经元在许多区域投射。 在小鼠中，以及在皮层区域中。以前对这些细胞连接性的研究受到阻碍 由于必须切片组织和填充细胞来产生形态，限制了我们对这些细胞的了解。在我的第一个目标， 我计划使用组织清除和光片显微镜来确定目标突触后区域来解决这些问题 这些细胞。我将用双光子记录这些细胞在行为上的活动来补充这一点。 国家确定影响下游地区的活动模式。 在我的第二个目标中，我将使用光遗传学和生物学方法对长距离抑制神经元进行体内功能表征。 电生理学体外研究表明，长距离抑制神经元在慢波睡眠期间是活跃的， 低频振荡。我将在体内进行细胞外电生理学，同时使用光遗传学工具， 操纵长距离抑制神经元的活动。我将使用兴奋性视蛋白和频率调制刺激 和抑制性视蛋白。我将测量单个单元和网络振荡对这种刺激的反应。我会 在长距离抑制神经元和其他神经元类型中进行操作，以显示测试结果的特异性。 假设这些细胞调节低频振荡的产生。 这两个目标一起提供了第一个在体内的远程抑制性神经元的活性表征。当 完成后，我将能够将这种细胞类型的连接，形态和活动模式联系起来，以了解其作用 皮层回路中的这种细胞类型。

Project Summary Cortical activity changes dramatically upon changes in behavioral state of an animal with different behavioral states, such as sleep and wake, having profound impact on cortical processing. The circuitry responsible for sensing behavioral state and modifying cortical activity to generate cortical states remains unknown. However, inhibitory neurons (INs) have been recently implicated in this role. Interestingly, both dysregulation of behavioral states and disruptions in INs are hallmarks of major neuropsychiatric disorders. Here, I propose that a specific sub type of inhibitory neuron in the cortex plays a role in the generation of low-frequency oscillations, a hallmark of multiple cortical states. I propose that the long-range inhibitory neurons of the cortex play a crucial role in the generation of low-frequency oscillations. Long-range inhibitory neurons are highly distinct from other cell types in the cortex both in terms of their morphology and gene expression. While other INs in the cortex project locally, long-range inhibitory neurons project across many millimeters, in the mouse, and across cortical areas. Previous studies of the connectivity of these cells have been hampered by the necessity to slice tissue and fill cells to generate morphologies limiting our knowledge of these cells. In my first aim, I plan to address these issues using tissue clearing and light sheet microscopy to determine the postsynaptic areas targeted by these cells. I will compliment this with 2-photon recordings of the activity of these cells performed across behavioral states to determine the activity patterns affecting downstream areas. In my second aim, I will perform in vivo function characterizations of long-range inhibitory neurons using optogenetics and electrophysiology. Ex-vivo studies suggest that long-range inhibitory neurons are active during slow wave sleep, a period of low-frequency oscillations. I will perform in vivo extracellular electrophysiology while using optogenetic tools to manipulate the activity of long-range inhibitory neurons. I will use excitatory opsins with frequency modulated stimulation and an inhibitory opsin. I will measure the responses of single units and network oscillations to this stimulation. I will perform manipulations in long-range inhibitory neurons and other neuronal types to show specificity of results testing the hypothesis that these cells regulate the generation of low-frequency oscillations. Together these two aims provide the first in vivo characterizations of the activity of long-range inhibitory neurons. When completed, I will be able to relate the connectivity, morphology, and activity patterns of this cell type to understand the role of this cell type in cortical circuits.