PEPTIDERGIC NEURONS OF THE PRIMATE RETINA

描述(改编自申请者的摘要)：研究的目标是 描述为侏儒和阳伞提供输入的神经回路 神经节细胞产生了两个主要的并行处理流 猕猴的视觉路径。因为猕猴的视网膜非常 与人类相似的结果也将有助于理解 人类的视觉。特定目标1研究已知的侏儒细胞 投射到LGN的小细胞层，并被认为有助于 到空间视觉，到红绿色觉。他们的输入来自Long和 通过侏儒双极细胞的中波长锥体已经被很好地描述了 在中央视网膜。在上一个资助期内，对侏儒的投入 外周视网膜的神经节细胞也被研究过，还有两个无长突细胞 对该途径中的细胞进行了描述，并将在建议的 实验。工作假说是这两者之间的相互作用 无长突细胞对于解释特定颜色的环境是必不可少的 侏儒神经节细胞的反应。特指2调查遮阳伞 投射到LGN大细胞层的神经节细胞 有助于感知运动以及感知的其他方面。 在之前的资助期间，阳伞细胞的突触输入是 描述，并在提供这些输入的两个地点发现缝隙连接 细胞。工作假说是缝隙连接是 这一途径，以及拟议的实验将识别出更多类型的 突触前神经元，并检查潜在的电耦合部位。 具体目标3是制作一个真实的神经电路的计算机模型 是在解剖学研究中发现的，为神经节细胞提供输入。这个 模型的输入电路到侏儒神经节细胞将测试新的 解释其锥体特定环境的假设，而没有 视锥细胞特异的连接，除了已知存在于视网膜中央的 视锥细胞、侏儒双极细胞和侏儒神经节细胞。阳伞细胞更多 比侏儒细胞对亮度对比度更敏感，反应更短暂。 与侏儒细胞不同的是，它们也与 相同的亚型。建模研究将检验假设，即 对侏儒和副神经节细胞的突触输入可以解释许多 这些生理上的差异。

DESCRIPTION (Adapted from applicant's abstract): The goal of the research is to describe the neural circuits that provide input to the midget and parasol ganglion cells that give rise to the two major parallel processing streams in the macaque visual pathway. Because the retina of macaque monkey is very similar to that of humans, the results will also be helpful for understanding human vision. Specific aim 1 investigates midget cells that are known to project to the parvocellular layers of the LGN, and are thought to contribute to spatial vision, and to red-green color vision. Their inputs from long and medium wavelength cones via midget bipolar cells have been well characterized in the central retina. During the last funding period, inputs to midget ganglion cells were investigated in peripheral retina as well, and two amacrine cells in this pathway were described and will be identified in the proposed experiments. The working hypothesis is that interactions between these two amacrine cells are essential to account for the color-specific surround responses of midget ganglion cells. Specific aim 2 investigates parasol ganglion cells that project to the magnocellular layers of the LGN and contribute to perception of motion as well as other aspects of perception. During the prior funding period, synaptic inputs to parasol cells were described, and gap junctions were found at two sites providing input to these cells. The working hypothesis is that gap junctions are a common feature of this pathway, and the proposed experiments will identify more types of presynaptic neurons and examine potential sites of electrical coupling. Specific aim 3 is to make a realistic computer model of the neural circuits that were found in anatomical studies to provide input to ganglion cells. The model of the input circuit to midget ganglion cells will test the novel hypothesis that accounts for their cone-specific surrounds without cone-specific connections except those known to exist in central retina between cones, midget bipolar cells and midget ganglion cells. Parasol cells are more sensitive than midget cells to luminance contrast and respond more transiently. Unlike midget cells, they also fire in synchrony with other parasol cells of the same subtype. The modeling studies will test hypotheses that differences in synaptic inputs to the midget and parasol ganglion cells can account for many of these physiological differences.