RETINAL CIRCUITS AND SYNAPSES FOR PRIMATE COLOR VISION

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 人类的三色视觉来自“蓝-黄”和“红-绿”视锥驱动通道。蓝-黄通道比较短（S）与长（L）和中（M）波长敏感型光感受器类型的量子捕获，而红-绿通道比较L和M视锥的量子捕获。色觉开始于复杂的视网膜回路，并投射到外侧膝状体核（LGN）的小细胞层，随后投射到视觉皮层。在灵长类动物的视网膜中，已经研究了两类神经节细胞在蓝黄和红绿色觉中的作用：小双层细胞和侏儒细胞。然而，几个关键的问题仍然没有答案的兴奋性和抑制性突触输入的颜色编码的作用，在灵长类动物视网膜的实验方法受到限制。对于拟议的项目，我们将使用我们成熟的猕猴体外视网膜制备，这是理解人类视觉的理想模型，以确定兴奋性和抑制性神经传递在蓝黄色和红绿色编码中的作用。为了实现这些目标，将使用结合兴奋性和抑制性受体的药理学操作、电导分析以及短（S）、中（M）和长（L）波长视锥选择性刺激的松散膜片钳和全细胞膜片钳记录靶向小型双层和小型神经节细胞，以确定S-、L-和M-视锥驱动的兴奋和抑制对神经节细胞的作用。一系列的实验已经被设计来表征离子型谷氨酸受体（AMPA型和NMDA型）在彩色对比敏感度中的作用。先前的工作已经证明AMPA和NMDA受体在无色编码中的互补作用，我们的初步数据表明，这些受体对颜色编码也很重要。将进行两种类型的视网膜内抑制（前馈和交叉）在颜色编码中的作用的直接测试。

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. Human trichromatic color vision arises from 'blue-yellow' and 'red-green' cone-driven channels. The blue-yellow channel compares the quantal catch of short- (S) with long- (L) and middle- (M) wavelength-sensitive photoreceptor types, and the red-green channel compares the quantal catch of L and M cones. Color vision begins in the complex retinal circuitry and in the projection to the parvocellular layers of the lateral geniculate nucleus (LGN) and, subsequently, to visual cortex. In the primate retina, two ganglion cell classes have been studied for their roles in blue-yellow and red-green color vision: the small bistratified and midget cell, respectively. However, several key questions remain unanswered about the roles of excitatory and inhibitory synaptic input in color-coding, as experimental approaches in the primate retina have been limited. For the proposed project, we will use our well-established in vitro retina preparation from the macaque monkey, an ideal model for understanding human vision, to determine the roles of excitatory and inhibitory neurotransmission in blue-yellow and red-green chromatic coding. To achieve these goals, small bistratified and midget ganglion cells will be targeted using loose-patch and whole-cell patch-clamp recording combined with pharmacological manipulation of excitatory and inhibitory receptors, conductance analysis, and short- (S), middle- (M), and long- (L) wavelength cone-selective stimuli to determine the roles of S-, L-, and M-cone-driven excitation and inhibition to a ganglion cell. A series of experiments have been designed to characterize the roles of ionotropic glutamate receptors (AMPA- and NMDA-type) in chromatic contrast sensitivity. Previous work has demonstrated complementary roles for AMPA and NMDA receptors in achromatic coding and our preliminary data suggests that these receptors are also important for color-coding. Direct testing of the roles of two types of inner retinal inhibition, feedforward and crossover, in color-coding will be performed.