CIRCUITRY OF THE MIDGET AND PARASOL RECEPTIVE FIELD

侏儒和阳伞接受区的电路

• 批准号: 8357582
• 负责人: DENNIS MICHAEL DACEY
• 金额: $ 15.51万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8357582
• 关键词: Carbenoxolone; Cells; Cobalt; Code; Color; Drug usage; Funding; Gap Junctions; Goals; Grant; Measures; National Center for Research Resources; Primates; Principal Investigator; Protocols documentation; Research; Research Infrastructure; Resources; Retinal; Retinal Cone; Series; Signal Transduction; Source; Stimulus; Synapses; Time; United States National Institutes of Health; Weight; cell type; cost; ganglion cell; presynaptic; receptive field; research study; transmission process

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The goal of this project is determine how the receptive field surround is established at the level of the ganglion cell and how the surround contributes to color-coding by identifying the cone inputs to the surround. The presynaptic hypothesis predicts that the creation of the cone bipolar center-surround organization is the critical locus for cone opponency. We showed for the first time in a mammalian retina that cone bipolar cells have robust center-surround organization comparable to their ganglion cell counterparts. We then undertook a series of experiments to attempt to selectively block ganglion cell surrounds. We found, in parasol cells, that either cobalt or the gap-junction blocker, carbenoxolone, selectively reduces surround antagonism. We are now using these drugs to assess the receptive field surround contribution to color-opponency in a number of ganglion cell classes. In a second series of experiments, we developed a new stimulus protocol to measure the strength and sign of L, M and S-cone inputs to the receptive field surrounds of midget and parasol ganglion cell types. The specific goal was to assess how cone signal weighting may be altered during transmission from outer to inner retinal circuitry. We showed that there are no gain changes from the horizontal-bipolar cell level to the ganglion cell surround and concluded that cone type-specific changes in synaptic gain are not a likely mechanism for generating color-opponent signals.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供。子项目的主要支持 并且子项目的主要研究者可能是由其他来源提供的， 包括其他 NIH 来源。 子项目可能列出的总成本 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 该项目的目标是确定如何在神经节细胞水平上建立感受野周围环境，以及通过识别周围环境的锥体输入，周围环境如何有助于颜色编码。突触前假说预测视锥细胞双极中心-环绕组织的形成是视锥细胞对抗的关键部位。我们首次在哺乳动物视网膜中证明，视锥双极细胞具有与神经节细胞对应物相当的强大的中心周围组织。然后我们进行了一系列实验，试图选择性地阻断神经节细胞周围。我们发现，在伞细胞中，钴或间隙连接阻断剂卡宾索隆选择性地减少周围拮抗作用。我们现在使用这些药物来评估感受野周围对许多神经节细胞类别中颜色对抗的贡献。 在第二系列实验中，我们开发了一种新的刺激方案来测量侏儒和伞神经节细胞类型的感受野周围的 L、M 和 S 锥体输入的强度和符号。 具体目标是评估视锥细胞信号权重在从视网膜外电路传输到内视网膜电路期间如何改变。我们表明，从水平双极细胞水平到神经节细胞周围没有增益变化，并得出结论，突触增益中视锥细胞类型特异性的变化不是产生颜色对手信号的可能机制。