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Neurophysiology of the Fovea

中央凹的神经生理学

基本信息

批准号：
10238108
负责人：
Michael Tri Hoang Do
金额：
$ 42.92万
依托单位：
BOSTON CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-01 至 2023-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10238108
关键词：
Accounting Acute Address Anatomy Attention Awareness Axon Benchmarking Biological Biophysical Process Blindness Cell physiology Cells Characteristics Clinical Treatment Complement Computer Models Cone Conscious Contrast Sensitivity Data Data Set Dependence Diagnosis Eagles Electrophysiology (science)Eye Eye Movements Face Feedback Frequencies Genome Health Human Image Individual Ion Channel Gating Kinetics Knowledge Light Macaca Macular degeneration Measures Membrane Methods Modeling Mus Muscle Cells Nature Neurons Noise Optics Output Performance Peripheral Pharmacology Photons Phototransduction Physiology Play Positioning Attribute Presynaptic Terminals Primates Property Publications Publishing Reading Resolution Retina Retinal Cone Retinal Ganglion Cells Role Sensory Shapes Signal Transduction Stimulus Structure Testing Tissues Vertebrate Photoreceptors Vision Visual Visual Acuity Work absorption biological systems experimental study fovea centralis improved insight macula neuronal cell body neurophysiology patch clamp peer preservation response sight restoration single-cell RNA sequencing statistics visual performance visual stimulus voltage voltage clamp

项目摘要

Most conscious vision in humans and other primates begins with the fovea, a specialization of the central retina that encodes the image in exceptional detail. The cone photoreceptors of the fovea are tailored for high spatial acuity. They have a tiny cross-section and dense packing, allowing them to form an extremely fine pixel array. Foveal cones also extend long axons that allow downstream cells to be displaced laterally from the light path, providing direct access to the visual image. Each of the principal output neurons of the fovea—the midget retinal ganglion cells (RGCs)—is also driven by a single cone, preserving spatial resolution. By contrast, cones of the peripheral retina are broad, widely spaced, and positioned behind layers of cell bodies and processes; additionally, more than a dozen peripheral cones converge upon single midget RGCs, further reducing spatial resolution. These anatomical specializations of the fovea have been recognized for decades. The overarching hypothesis of this proposal is that foveal cones also possess functional specializations for high-acuity vision. Indeed, a recent publication has indicated that phototransduction is more prolonged in foveal than peripheral cones. The consequences of this distinction are not yet clear. Much depends on how the light responses of foveal cones are shaped downstream of phototransduction, by voltage-gated ion channels (VGICs). Experiments proposed in Aim 1 test the hypothesis that VGICs complement the distinct kinetics of foveal phototransduction. The ability to encode fine spatial detail also depends on the signal/noise ratio. Achieving high signal/noise would appear especially important for foveal cones, which have little opportunity to pool their signals to improve the response fidelity of foveal midget RGCs. In Aim 2, we test the hypothesis that the signal/noise of foveal cones is increased at multiple stages, including the currents produced by phototransduction and VGICs as well as their effect on the membrane voltage at the soma and synaptic terminal. For both aims, our principal approach is to apply patch-clamp electrophysiology to foveal and peripheral cones that are embedded within retinal circuitry or have been acutely dispersed into single cells. These experiments are complemented by computational modeling. We maintain an experimental platform that supplies us with foveal and peripheral tissue for quantitative analysis. The work proposed here constitutes early steps toward a full understanding of the fovea at the level of cellular neurophysiology.

人类和其他灵长类动物的大多数有意识视觉都是从中央凹开始的，这是中央凹的一个特化部位