COLOR AND CONNECTIVITY IN CONE PHOTORECEPTORS

将视网膜上的图像转换为对 物理物体开始于将光子能量转化为 杆状和锥状感光器中的电信号。在离开之前 眼睛比较-1亿个光感受器的信号， 压缩、平均、分析并缩减为100万个通道 信息在视神经中流动。这些神经节细胞神经纤维 将形状、亮度、颜色和运动信息编码为 动作电位。光感受器曾经被认为是 独立的光传感器，就像照片中的单个颗粒 电影，但这似乎不是真的。事实上，光感受器， 含有视觉信息的第一层神经细胞正在接触 彼此之间，因此也可能对第一个 通过神经系统进行视觉信息分析的水平。 这笔拨款将检验两个假设： 假设一：人类红色和绿色锥体色素的亚型是 每个锥体细胞随机表达一个基因。对人类的直接审视 锥体光谱敏感性将与分析的序列进行比较 视觉色素蛋白质。电子记录会给出准确的 光谱灵敏度函数的描述以及并行的 表达的视觉色素蛋白的数量和种类将是 下定决心。具体的问题是：是什么导致了光谱敏感性 人体锥体？是视觉色素的多个副本和变种 视色素基因的功能表达限制在1% 手机吗？ 假设2：锥体的光谱类型是不同的细胞类型， 形成排除其他光谱类锥体的耦合网络。 将使用生理学和解剖学技术来评估大小 以及锥体感受野的光谱特性，这就需要 突触接触强度的定量测定 相邻的圆锥体。三类光谱锥体的存在 人类提出了一个问题，即眼睛如何保持其 可能发生信息汇集时的三种颜色“通道” 即使在光感受器层本身。以下问题将 被接近：(1)吃哺乳动物的锥体，它们的锥体与其 邻近的光感受器？(2)是突触与 邻近的光感受器仅限于相同光谱类型的光感受器？(3) 在人类和非人类哺乳动物中，兴奋的横向传播是什么 锥体，和(4)是侧突的物理尺寸 相邻的光感受器之间的数量关系 生理上测量的细胞的空间常数？

The transformation of an image on the retina into a perception of physical objects begins with the transduction of photon energy into electric signals in rod and cone photoreceptors. Prior to leaving the eye the signals of the -100 million photoreceptors are compared, compressed, averaged, analyzed and reduced into 1 million channels of information flowing in the optic nerve. These ganglion cell nerve fibers carry the information of form, brightness, color and motion encoded as action potentials. Photoreceptors were once thought to act as independent light sensors, like the individual grains of a photographic film, but this appears not to be true. In fact the photoreceptors, the first layer of nerve cells containing visual information, are in contact with one another and therefore may also be responsible for the first level of visual information analysis by the nervous system. There are two hypotheses that will be tested with this grant: Hypothesis I: The subtypes of human red and green cone pigments are expressed randomly one gene per cone cell. A direct examination of human cone spectral sensitives will be compared to the analyzed sequences of the visual pigments proteins. Electrical recording will give the precise descriptions of the spectral sensitivity functions and in parallel the number and variety of visual pigment proteins expressed will be determined. Specific questions are: What ate the spectral sensitivities of human cones? Are multiple copies and varieties of the visual pigment genes functionally expressed of visual pigment genes limited to one per cell? Hypothesis 2: Spectral classes of cones are distinct cell types, that form coupled networks which exclude other spectral classes of cones. Physiologic and anatomic techniques will be used to evaluate of the size and spectral characteristics of a cone's receptive field, this entails a quantitative determination of the strength of synaptic contact between neighboring cones. The presence of three spectral classes of cones in humans raises the issue of how the eye maintains the integrity of its three color "channels" when pooling of information is likely to occur even within the photoreceptor layer itself. The following questions will be approached: (1) Ate mammalian cones eclectically coupled to their neighboring photoreceptors? (2) Are synaptic interactions with neighboring photoreceptor limited to those of the same spectral type? (3) What is the lateral spread of excitation in human and non-human mammalian cones, and (4) are the physical dimensions of the lateral processes between neighboring photoreceptors quantitatively related to the physiologically measured space constant of the cell?