Two-photon optical control of astrocytic function

描述（由申请人提供）：星形胶质细胞不仅仅是电路的被动成员，而且它们也可能直接参与神经元计算。事实上，星形胶质细胞非常适合在神经回路中扮演一个潜在的广泛角色：它们几乎完全覆盖中枢神经系统，通过间隙连接连接成一个广泛的合胞体，单个星形胶质细胞的过程可以连接多达数万个突触。事实上，我们最近已经证明，即使是对单个星形胶质细胞的刺激也能控制皮层中全回路的神经元同步。研究星形胶质细胞的工具明显不如研究神经元功能的工具发达，因此，大多数关于星形胶质细胞信息处理的研究都是有限和不完整的。星形胶质细胞研究人员需要有选择性地测量和操纵体内星形胶质细胞功能的方法。双光子激发可以穿透活体组织，同时提供单细胞分辨率，结合兼容的光化学或光遗传探针，可能是未来星形胶质细胞研究的理想技术平台。我们建议开发新的双光子和计算工具，利用新的星形胶质细胞特异性脑虹小鼠系，提供体内神经回路中星形胶质细胞功能的亚细胞和电路水平分析。这些工具包括双光子光遗传学和笼化化合物，星形胶质细胞组三维成像方法，以及揭示星形胶质细胞与神经元在电路中相互作用的计算算法。有了这个奖项，我们将提供

DESCRIPTION (provided by applicant): Astrocytes are not merely passive members of the circuit, but that they may also be directly involved with neuronal computation. Indeed, astrocytes are well suited to a potential widespread role in the circuit: they tile the CNS with near- complet coverage, are connected into an extensive syncytium via gap junctions, and processes from a single astrocyte can contact up to tens of thousands of synapses. In fact, we have recently shown how even the stimulation of single astrocyte can control circuit-wide neuronal synchronizations in the cortex. Tools to study astrocytes are significantly less developed than those available to investigate neuronal function and, consequently, most research on astrocytic information processing has been limited and incomplete. Astrocyte researchers need methods to selectively measure and manipulate the function of astrocytes in vivo. Two-photon excitation, which penetrates living tissue while affording single-cell resolution, combined with compatible optochemical or optogenetic probes, could be an ideal technical platform for future astrocyte research. We propose to develop novel two-photon and computational tools to provide subcellular and circuit-level analysis of astrocytic function in neural circuits in vivo, using a nvel astrocyte-specific Brainbow mouse line. These tools include two- photon optogenetic and caged compounds, methods to image groups of astrocytes in 3D, and computational algorithms to reveal interactions of astrocytes with neurons in the circuit. With this award, we will provide the astroglia community with a wide range of optical and computational tools that can be readily adapted for use in vivo. This work will enable the investigation of the roles of astrocytes in shaping neuronal activity in the cortical microcircuit and beyond, and thus could have a fundamental impact on how we view neuro-glia processing, as well as on solidifying the role of an overlooked circuit constituent-the astrocyte-in cortical synchrony and computation. Finally, this work could introduce a novel potential means to assay or control neuronal function for potential therapeutic purposes: through specific activation of astrocytes.