The role of long-range inhibitory neurons in cortical circuits

项目摘要 具有不同行为状态的动物的行为状态发生变化时，皮质活动会发生显著变化，例如 如睡眠和清醒，对大脑皮层的处理有深远的影响。负责检测行为状态的电路 修改皮质活动以产生皮质状态仍然是未知的。然而，抑制性神经元(INS)已经被 最近与这个角色有牵连。有趣的是，行为状态的失调和INS的紊乱都是标志 严重的神经精神障碍。在这里，我认为大脑皮层中一种特殊类型的抑制性神经元在其中起作用 在低频振荡的产生中，这是多种大脑皮层状态的标志。我认为长程抑制作用 大脑皮层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大脑皮层的其他细胞类型有很大的不同 基因表达。当皮质中的其他INS局部投射时，长程抑制性神经元投射到许多 毫米，在老鼠体内，并横跨皮质区域。以前对这些细胞的连接性的研究受到了阻碍 由于需要切片组织和填充细胞来生成限制我们对这些细胞的知识的形态。在我的第一个目标， 我计划使用组织清除和光片显微镜来解决这些问题，以确定目标突触后区域 被这些细胞。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 各国应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 电生理学。体外研究表明，长程抑制性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，同时使用光遗传工具来 操纵长程抑制性神经元的活动。我将使用带有调频刺激的兴奋性眼球 和一种抑制性视蛋白。我将测量单个单元和网络振荡对这种刺激的反应。这就做 在远程抑制神经元和其他类型的神经元中执行操作，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。 这两个目标共同提供了长程抑制性神经元活动的第一个活体表征。什么时候 完成后，我将能够将这种细胞类型的连通性、形态和活动模式联系起来，以了解其作用 这种类型的细胞在大脑皮层回路中。

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.