Development of Retinal Receptive Fields

视网膜感受野的发育

• 批准号: 6801563
• 负责人: NORBERTO M GRZYWACZ
• 金额: $ 36.2万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-12-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6801563
• 关键词: Chelonia; brain electrical activity; calcium indicator; cell growth regulation; computer simulation; dark adaptation; dendrites; developmental neurobiology; electrophysiology; fluorescence microscopy; imaging /visualization /scanning; mathematical model; neostigmine; neural information processing; neural plasticity; neurons; retinal ganglion; synapses; visual fields; visual pathways; visual phototransduction; visual stimulus

DESCRIPTION (provided by applicant): An important property of visual neurons is their receptive-field size. One long-term goal of the proposed research is to understand the developmental mechanisms controlling the growth of retinal receptive fields. We recently established that one such mechanism depends on the spontaneous waves of activity that sweep developing retinas. Four hypotheses for this mechanism involve dendritic-tree growth, optimization of receptive-field size, critical period for growth, and inter-cell competition. We will test these hypotheses in the turtle retina with four aims: 1) We will use intracellular recordings and dendritic staining to test whether spontaneous waves cause receptive fields of ganglion cells to grow by enlarging their dendritic trees. 2) Turtles will be reared in abnormal light environments to test through extracellular recordings whether receptive fields grow to a size optimized to average out noise, while not over-smoothing the image. 3) Ca2+ fluorescence will help us map the waves and ask how light affects them. 4) We will test whether receptive-field growth stops because of a critical period or of an inter-cell competition by increasing the intensity of dark-reared waves though the retinal implantation of drug-laced Elvax. This study could help understand several developmental pathologies affecting ganglion cells. These pathologies include retinopathy of prematurity, retinal degeneration, refsum disease, Leber hereditary optic neuropathy, optic-nerve hypoplasia, and drusen of the optic disk. Besides understanding pathologies, unraveling ganglion-cell plasticity may help with a promising technique for one of their cures, namely, retinal transplantation. In such a transplantation, cells must "self-organize" as during development.

描述（由申请人提供）：视觉神经元的重要特性是它们的田间大小。拟议研究的一个长期目标是了解控制视网膜接受场生长的发展机制。我们最近确定，这样一种机制取决于扫除视网膜的自发性活性波。该机制的四个假设涉及树突树的生长，接受田间大小的优化，生长的关键时期和细胞间竞争。我们将以四个目标在乌龟视网膜中测试这些假设： 1）我们将使用细胞内记录和树突状染色来测试自发波是否会通过扩大其树突树来引起神经节细胞的接收场生长。 2）海龟将在异常的光环环境中饲养，以通过细胞外记录进行测试，无论接受场是否生长到优化的平均噪声尺寸，而不会超平光图像。 3）CA2+荧光将帮助我们绘制波浪并询问光如何影响它们。 4）我们将通过通过视网膜植入的视网膜植入来增加黑色射波的强度来测试由于关键时期的接收场生长是否停止，或者是在相互竞争的情况下停止的。 这项研究可以帮助理解几种影响神经节细胞的发育病理。这些病理包括早产，视网膜退化，refsum疾病，左骨遗传性视神经病变，视膜发育不全和视盘的DRUSEN。除了了解病理学外，脱离神经节的可塑性可能有助于一种有希望的技术，即视网膜移植。在这种移植中，细胞必须像发育过程中“自组织”。