Optical control of synaptic transmission for in vivo analysis of brain circuits and behavior

 描述（由申请人提供）：光遗传学通过使用异源表达的光门控离子通道和泵来刺激或抑制遗传选择的神经元的动作电位放电以确定其在脑回路和行为中的作用，从而彻底改变了神经科学。因为通过神经回路的信息流取决于 对于细胞间的突触传递，下一个重要的技术步骤是将光遗传学控制引入突触的神经递质受体。我们提出的光遗传药理学使这成为可能。在这种方法中，来自突触的遗传工程神经递质受体通道和G蛋白偶联受体（GCPR）用合成的光开关栓系配体（PTL）衍生化，从而通过光进行控制。我们的目标是发展这项新技术，以获得对突触传递和可塑性的光学控制，在活的大脑中的神经回路和行为的研究。 我们集中在两个基本的突触的大脑：兴奋性突触和抑制性GABA能突触。最初的一系列光调节谷氨酸和GABA受体已经被制造出来。这一系列将优化在体内使用和扩展，以获得这些突触的全面控制。受体被最小限度地修饰，具有使PTL附着成为可能的单点突变。因此，它们保持了对神经递质作出反应的正常能力。然而，它们可以被阻断以阻止正常的突触传递或诱导某些形式的可塑性，或者它们可以被激活以模仿传递或触发可塑性变化，具有细胞和亚型特异性以及高空间和时间精度。受体整合到突触中，并且控制可以在广泛的空间尺度上发挥作用，从单个突触前或突触后末端到一个或多个树突状分支，到单个或一组细胞，再到整个大脑区域。遗传操作的新方法允许修饰的受体在基因组上取代其野生型受体，精确复制大脑中内源性受体的数量和分布。光遗传药理学为理解健康和疾病中的大脑回路和行为提供了一种强有力的方法。

 DESCRIPTION (provided by applicant): Optogenetics has revolutionized neuroscience by making it possible to use heterologously expressed light-gated ion channels and pumps to stimulate or inhibit action potential firing of genetically selected neurons in order to define ther roles in brain circuits and behavior. Since the flow of information through neural circuits depends on synaptic transmission between cells, an important next technological step is to bring optogenetic control to the neurotransmitter receptors of the synapse. The Optogenetic Pharmacology that we propose makes this possible. In this approach genetically-engineered neurotransmitter receptor channels and G protein coupled receptors (GCPRs) from synapse are derivatized with synthetic Photoswitched Tethered Ligands (PTLs) and thereby made controllable by light. Our goal is to develop this new technology to gain optical control over synaptic transmission and plasticity in the living brain for studies of neural circuits and behavio. We focus on the two fundamental synapses of the brain: the excitatory glutamatergic synapse and inhibitory GABAergic synapse. An initial series of light-regulated glutamate and GABA receptors has already been made. This series will be optimized for in vivo use and expanded to obtain comprehensive control of these synapses. The receptors are minimally-modified, with a single point mutation enabling PTL attachment. Thus they retain their normal ability to respond to neurotransmitters. However, they can be blocked to prevent normal synaptic transmission or the induction of certain forms of plasticity, or they can be activated to mimic transmission or trigger plasticity changes, with cell and subtype specificity as well as high spatial and temporal precision. The receptors integrate into synapses, and control can be exerted across broad spatial scales, from individual pre- or postsynaptic terminals, to one or more dendritic branches, to individual or groups of cells, to entire brain regions. New methods for genetic manipulation allow the modified receptors to be genomically substituted for their wild-type counterparts, exactly replicating the number and distribution of endogenous receptors in the brain. Optogenetic Pharmacology provides a powerful approach for understanding brain circuits and behavior in health and disease.