Functional properties of amacrine cells in the mammalian retina

哺乳动物视网膜无长突细胞的功能特性

• 批准号: 10446557
• 负责人: William Rowland Taylor
• 金额: $ 40.09万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10446557
• 关键词: Acute; Amacrine Cells; Back; Blindness; Brain; Calcium; Cell Extracts; Cells; Characteristics; Chemical Synapse; Cone; Coupled; Data; Detection; Electrical Synapse; Electrophysiology (science); Eye; Gap Junctions; Gene Expression; Goals; Image; In Vitro; Inner Plexiform Layer; Interneurons; Investigation; Knowledge; Label; Learning; Light; Maps; Measures; Microscope; Molecular; Morphology; Motion; Mus; NOS1 gene; Neurons; Neurotransmitters; Nitric Oxide Synthase; Nitric Oxide Synthase Type I; Output; Pathologic; Photoreceptors; Physiological; Play; Population; Preparation; Process; Property; Prosthesis; Research; Retina; Retinal Ganglion Cells; Role; Signal Transduction; Slice; Stimulus; Synapses; Testing; Tracer; Vision; Visual; Work; antagonist; cell type; chemical release; ganglion cell; imaging approach; molecular imaging; motion sensitivity; neural network; neuronal cell body; neurotransmission; novel; novel therapeutics; object motion; optogenetics; patch clamp; postsynaptic; receptive field; relating to nervous system; response; retinal neuron; signal processing; sound; spatiotemporal; transmission process; visual processing

PROJECT SUMMARY This project proposes to study the roles of specific amacrine cells (ACs) in the visual signal processing performed by the mammalian retina. Electrophysiological recordings of light evoked activity will be made from ACs, ganglion cells (GCs), and bipolar cells in intact in vitro whole- mount and slice preparations of mouse retina maintained at photopic adaptation levels. The functional properties of the cells will be probed using images projected onto the photoreceptors through the microscope objective. Patch-clamp recordings from amacrine and ganglion cell somas will be performed to measure the stimulus-evoked postsynaptic currents, postsynaptic potentials, and spiking responses. The project focusses on the elucidating the synaptic mechanisms underlying the receptive field properties of 3 genetically labelled amacrine cell types. Aims 1 and 2 examine the functional properties of two types of amacrine cells, so called NOS-1 and NOS-2 amacrine cells, which are identified by their expression of nitric-oxide synthase (NOS). Aim 1 will test the hypothesis that the NOS-1 ACs are key interneurons for controlling the strength of surround antagonism in GCs at scotopic light levels and that they exert their effects via GABAergic synaptic connections to AII ACs. We will make dual recordings between the NOS- 1 ACs and specific types of GCs, to directly test for indirect synaptic connections consistent with the proposed circuit. Aim 2 will examine the role of NOS-2 ACs in conferring motion-sensitivity to specific type of small-field GCs in the mouse. We will use optogenetic stimulation of ChR2 expressing NOS ACs to identify the postsynaptic targets. The postsynaptic targets will be identified morphologically and physiologically and inputs arising from NOS-2 ACs will be confirmed by paired recordings. Aim 3 focuses on a novel amacrine cell type that is one of 2 AC types that can be identified by their expression of the gene Gbx2. We will focus on the Gbx2+ ACs that stratify in sublamina 3 (S3) of the inner plexiform layer. The S3-Gbx2+ ACs are highly unusual because they appear to express none of the conventional inhibitory or excitatory neurotransmitters, indicating that they represent novel populations of so-called non-GABAergic, non-glycinergic (nGnG) ACs. Preliminary data show that these nGnG ACs are tracer coupled to bipolar cells. We will quantify the spatio-temporal receptive field properties of these nGnG S3- Gbx2+ ACs and will test the hypothesis that they make output via electrical synapses with bipolar cells. To do so, we will make patch-clamp recordings from cone bipolar cells in slice and measure depolarizing responses elicited by optogenetic stimulation (ChR2 expression) of the S3-Gbx2+ ACs. Overall, the results will reveal the functional properties and connectivity of the three AC types and will determine their roles in visual processing in the retina.

项目摘要 本项目拟研究特定的无长突细胞在视觉信号中的作用 哺乳动物视网膜进行的处理过程。光诱发的电生理记录 活性将在完整的体外全细胞中由AC、神经节细胞（GC）和双极细胞制成， 小鼠视网膜的固定和切片制备维持在明视适应水平。的 将使用投射到光感受器上的图像来探测细胞的功能特性 通过显微镜物镜。无长突和神经节细胞的膜片钳记录 胞体将被执行以测量刺激诱发的突触后电流，突触后 电位和尖峰反应该项目的重点是阐明突触 3种遗传标记的无长突细胞类型的感受野特性的潜在机制。 目的1和2研究两种类型的无长突细胞的功能特性，即所谓的NOS-1 和NOS-2无长突细胞，其通过一氧化氮合酶的表达来鉴定 （NOS）。目的1将检验NOS-1 AC是控制神经元凋亡的关键中间神经元的假设。 暗适应光水平下GC中周围拮抗作用强度及其作用 通过GABA能突触连接到AII AC。我们会在一号和二号之间进行双重录音- 1 AC和特定类型的GC，以直接测试与 提出的电路。目的2将研究NOS-2 AC在赋予运动敏感性中的作用， 小鼠中特定类型的小视野GC。我们将使用ChR 2的光遗传学刺激， 表达NOS AC以鉴定突触后靶点。突触后靶点将是 将在形态学和生理学上鉴定NOS-2 AC， 通过配对录音确认。目的3关注一种新的无长突细胞类型， 可以通过Gbx 2基因的表达来识别的类型。我们将重点介绍Gbx 2 + AC在内丛状层的亚层3（S3）中分层。S3-Gbx 2 + AC高度 不寻常，因为它们似乎不表达传统的抑制性或兴奋性 神经递质，表明它们代表了所谓的非GABA能的新群体， 非甘氨酸能（nGnG）AC。初步数据显示，这些nGnG AC是示踪剂偶联的， 双极细胞我们将量化这些nGnG S3的时空感受野特性， Gbx 2 + AC，并将测试它们通过双极电突触进行输出的假设 细胞为此，我们将对视锥双极细胞进行膜片钳记录 由S3-Gbx 2+的光遗传学刺激（ChR 2表达）引起的去极化反应 进化人总的来说，结果将揭示三个AC的功能特性和连接性 类型，并将决定其在视网膜视觉处理中的作用。