Receptive field properties of GABAergic neurons in mouse visual cortex

描述（由申请人提供）：为了理解皮质功能，必须确定在形态和神经化学上不同的单个皮质神经元中如何表征和处理包含在感觉输入中的信息。为了了解单个皮质神经元表征和加工特性的潜在机制，研究人员采用了一种盲体全细胞补丁记录技术来检测皮层神经元的感觉驱动的兴奋性和抑制性突触输入。这些研究结果为皮层神经元反应特性背后的突触回路机制提供了新的见解。尽管该技术可以与事后组织学方法相结合，重建所记录细胞的形态，但其盲目性在很大程度上限制了其在检查皮层中各种细胞类型方面的潜力，因为它通常会导致皮层中兴奋性锥体神经元的偏差采样。在这个探索性项目中，我们将研究一种揭示体内抑制性皮质神经元功能特性和突触输入的新技术，双光子成像引导斑块记录（TPGP），其中荧光标记的神经元通过双光子成像可视化，并专门针对斑块记录。这项技术得益于最近小鼠遗传学的发展，用荧光蛋白（如绿色荧光蛋白（GFP））标记特定类型的细胞，其表达由细胞类型特异性启动子控制。首先，我们将把这种记录技术应用于小鼠初级视觉皮层（V1）的核上层（L1-3）中gfp标记的gaba能中间神经元，以解决这些神经元的感受野特性，以及这些特性是如何通过视觉激活的兴奋性和抑制性突触输入的整合来决定的。

DESCRIPTION (provided by applicant): To understand cortical functions, it is essential to determine how information contained in sensory input is represented and processed in individual cortical neurons that are morphologically and neurochemically diverse. To understand mechanisms underlying the representational and processing properties of individual cortical neurons, a blind, in vivo, whole-cell patch-recording technique has been applied to examine sensory-driven excitatory and inhibitory synaptic inputs onto cortical neurons. Results from such studies have provided new insights into synaptic circuit mechanism underlying cortical neurons' response properties. Although this technique can be combined with post hoc histological methods to reconstruct the morphology of recorded cells, its blind nature largely limits its potential in examining various cell types in the cortex, since it normally results in a biased sampling of excitatory pyramidal neurons in the cortex. In this exploratory project, we will study a new technique for revealing functional properties and synaptic inputs of inhibitory cortical neurons in vivo, two-photon imaging guided patch recording (TPGP) in which fluorescently labeled neurons are visualized by two-photon imaging and specifically targeted for patch recording. This technique has benefited from recent development of mouse genetics in labeling cells of specific types with fluorescence proteins such as green fluorescence protein (GFP), with their expression controlled by cell-type specific promoters. At an initial step, we will apply this recording technique to GFP-labeled GABAergic interneurons in the supragranular layers (L1-3) of mouse primary visual cortex (V1), to address the receptive field properties of these neurons and how these properties are determined by the integration of visually activated excitatory and inhibitory synaptic inputs.