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

基本信息

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
项目类别：
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

项目摘要

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.

项目概要该项目旨在研究特定无长突细胞（AC）在视觉信号中的作用由哺乳动物视网膜进行的处理。光诱发的电生理记录活性将由完整的体外全细胞中的 AC、神经节细胞 (GC) 和双极细胞产生小鼠视网膜的安装和切片制剂保持在明视适应水平。这将使用投射到感光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将进行体细胞测量刺激诱发的突触后电流、突触后电流潜力和尖峰反应。该项目的重点是阐明突触 3种基因标记的无长突细胞类型感受野特性的潜在机制。目标 1 和 2 检查两种无长突细胞（即 NOS-1）的功能特性和 NOS-2 无长突细胞，通过一氧化氮合酶的表达来识别（NOS）。目标 1 将检验以下假设：NOS-1 AC 是控制 GC 在暗光水平下周围拮抗作用的强度及其发挥作用通过与 AII AC 的 GABA 能突触连接。我们将在 NOS- 之间进行双重录音 1 AC 和特定类型的 GC，直接测试间接突触连接，与所建议的电路。目标 2 将研究 NOS-2 AC 在赋予运动敏感性方面的作用小鼠体内特定类型的小视野 GC。我们将使用 ChR2 的光遗传学刺激表达 NOS AC 来识别突触后目标。突触后目标将是从形态学和生理学角度进行识别，NOS-2 AC 产生的输入将被通过配对录音证实。目标 3 重点关注一种新型无长突细胞类型，它是 2 AC 中的一种可以通过 Gbx2 基因的表达来识别的类型。我们将重点关注 Gbx2+ 在内丛状层的亚板 3 (S3) 中分层的 AC。 S3-Gbx2+ AC 高度不寻常，因为它们似乎不表达任何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。初步数据表明，这些 nGnG AC 与示踪剂耦合双极细胞。我们将量化这些 nGnG S3-的时空感受野特性 Gbx2+ 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，我们将从切片中的视锥双极细胞进行膜片钳记录并测量 S3-Gbx2+ 的光遗传学刺激（ChR2 表达）引起的去极化反应空调。总体而言，结果将揭示三个 AC 的功能特性和连接性类型并将决定它们在视网膜视觉处理中的作用。