Astrocytic regulation of neuronal synchronization

描述（由申请人提供）：神经元同步化的星形胶质细胞调节。 对星形胶质细胞的功能了解甚少，它们作为神经元支持者的传统作用仅捕获星形胶质细胞可能具有的许多功能输出的一小部分。最近对星形胶质细胞的研究揭示了其在突触传递中的重要作用，但其在整个回路中的作用研究较少，部分原因是缺乏回路水平的研究。 星形胶质细胞和神经元之间相互作用的测定。 使用双光子成像，我们最近发现，在新皮层脑切片中，刺激单个星形胶质细胞可以导致广泛的神经元同步，以UP状态的形式。相反，通过将BAPTA注射到单个星形胶质细胞中来阻断星形胶质细胞信号传导可以减少自发神经元UP状态的数量。 我们建议测试在一系列的直接实验，如果星形胶质细胞调节UP状态在体内。我们已经开发了新的双光子和遗传技术，使我们能够成像和操纵体内星形胶质细胞的活动，并研究它如何与神经元UP状态相关。我们的中心假设是星形胶质细胞的活动先于UP状态的发生，并且与UP状态的发生有因果关系。 具体地，在第一个目标中，我们将使用SLM对Brainbow小鼠的UP状态期间的神经元和星形胶质细胞活性进行快速双光子钙成像，其中星形胶质细胞区域被标记，并检查星形胶质细胞和神经元的活性之间是否存在时空相关性。在第二个目标中，我们将光学刺激星形胶质细胞，使用鲁比-谷氨酸，IP 3或ChR 2光活化的双光子释放，并测试这是否增加或改变自发UP状态。 我们提出的工作可以在体内星形胶质细胞功能和神经元同步化之间建立因果关系，从而为星形胶质细胞提供一种新的回路水平的功能作用。UP状态被认为是慢波睡眠和“静息状态”fMRI信号的基础，因此我们的研究可能直接涉及星形胶质细胞在这些全球大脑状态的电路机制。 我们的团队拥有独特的光学和电路神经科学技能，这项研究可以为星形胶质细胞的研究引入新的方法。

DESCRIPTION (provided by applicant): Astrocytic regulation of neuronal synchronization. The function that astrocytic glia play is poorly understood, and their traditional role, as supportive of neurons, captures only a small part of many functional outputs that astrocytes may have. Recent research on astrocytes has revealed important effects on synaptic transmission, but their role in the circuit as a whole has been less studied, partly due to lack of circuit-level assays of the interaction between astrocytes and neurons. Using two-photon imaging, we have recently discovered that, in neocortical brain slices, stimulation of a single astrocyte can lead t widespread neuronal synchronization, in the form of UP states. Conversely, blocking astrocytic signaling by the injection of BAPTA into individual astrocytes can reduce the number of spontaneous neuronal UP states. We propose to test in a series of direct experiments if astrocytes regulate UP states in vivo. We have developed new two-photon and genetic techniques that enable us to image and manipulate the activity of astrocytes in vivo and examine how it relates to neuronal UP states. Our central hypothesis is that the activity of astrocytes precedes, and is causally related, to the occurrence of UP states. Specifically, in a first aim we will perform fast two-photon calcium imaging, with SLMs, of neuronal and astrocytic activity during UP states in Brainbow mice where astrocytic territories are labeled, and examine whether there are spatio- temporal correlations between the activity of astrocytes and neurons. In a second aim we will optically stimulate astrocytes, using two-photon uncaging of RuBi- glutamate, IP3 or ChR2 photoactivation, and test whether this increases or alters spontaneous UP states. Our proposed work could establish a causal link between astrocytic function and neuronal synchronization in vivo, thus providing a novel circuit-level functional role for astrocytes. UP states are thought to underlie slow-wave sleep and "resting state" fMRI signals, so our research could directly involve astrocytes in the circuit mechanisms of those global brain states. Our group has a unique combination of optical and circuit neuroscience skills and this research could introduce novel approaches into the study of astroglia.