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 该项目建议研究特定的无长束细胞（AC）在视觉信号中的作用 由哺乳动物视网膜进行的处理。唤起光的电生理记录 活性将由ACS，神经节细胞（GCS）和双极细胞制成 小鼠视网膜的安装和切片制剂保持在光波自适应水平。这 将使用投影到光感受器上的图像探测单元的功能特性 通过显微镜目标。斑块钳录音来自两次和神经节细胞的录音 将进行SOMAS以测量刺激诱发的突触后电流，突触后刺激性 潜力和尖峰反应。该项目的重点是阐明突触 3种遗传标记的无链氨酸细胞类型的接受场特性的基础机制。 目标1和2检查两种类型的无长束细胞的功能特性，所谓的NOS-1 和NOS-2小节细胞，它们通过其表达一氧化物合酶的表达来鉴定 （NOS）。 AIM 1将检验NOS-1 ACS是控制的关键中间神经元的假设 在Scotopic Light水平上GC中周围拮抗作用的强度，并发挥作用 通过GABA能突触连接到AII ACS。我们将在nos-之间进行双重录音 1 AC和特定类型的GC，直接测试与间接突触连接一致 提出的电路。 AIM 2将检查NOS-2 AC的作用在赋予运动敏感性中 小鼠中的特定类型的小型GC。我们将使用CHR2的光遗传学刺激 表达NOS ACS以识别突触后靶标。突触后目标是 从形态和生理上鉴定出来，由NOS-2 ACS引起的输入将是 通过配对录音确认。 AIM 3专注于2 AC之一的新型无大细胞类型 可以通过基因GBX2表达来识别的类型。我们将专注于GBX2+ 在内丛状层的Sublamina 3（S3）中分层的AC。 S3-GBX2+ AC高度 不寻常，因为它们似乎没有表达任何常规抑制或兴奋性 神经递质，表明它们代表了所谓的非gabaergic的新种群， 非甘氨酸能（NGNG）ACS。初步数据表明，这些NGNG ACS示踪剂耦合到 双极细胞。我们将量化这些NGNG S3-的时空接受场特性 GBX2+ ACS，并将检验以下假设，即它们通过双极 细胞。为此，我们将在切片中从锥双极细胞中制作贴片钳记录并测量 S3-GBX2+的光遗传刺激（CHR2表达）引起的去极化反应 ACS。总体而言，结果将揭示三个AC的功能特性和连通性 类型并将确定它们在视网膜中视觉处理中的作用。