THALAMIC CONTROL OF CORTICAL VISUAL PROCESSING

视网膜信号通过大脑外侧区传递到大脑皮层 膝状核(LGN)。LGN部分地分为几个层 根据眼睛和视网膜神经节的功能类别来分离这些信号 手机。在猫身上，不同的层次也会有不同的程度 单个中继细胞将多个视网膜细胞的输出相加，并且 因此，他们以牺牲空间为代价获得敏感性的程度 决议。该项目的长期目标是了解如何和 为什么将LGN组织为层，这些通道对此有何贡献 感知和视觉运动行为，信息是如何传递的 它们整合在大脑皮层中，以及中枢如何反馈给LGN 动态调节信息向皮质的传输。投稿 对于视觉运动行为的各个层，将通过简短的 在执行眼球运动任务的猫身上，使选定的层失活。至 测试LGN细分在多大程度上不同的假设 专用于高敏感度或高敏感度的视力、灭活 将在强调空间或空间重要性的条件下完成 分辨率或弱光视觉。将使用类似的范例来测试 假设不同LGN层的相对影响 大脑皮层活动随任务需求和适应水平的不同而变化。 背侧LGN层永久性损害合并可逆性 中心层的失活以检查恢复的性质 功能似乎发生了这样的损害。这种新颖的形式 可塑性可能揭示由以下原因造成的感知缺陷 异常，特别是传入的眼球跳动。因为 扫视的目的是将感兴趣的目标移动到中央视网膜 代表中央视网膜的大脑区域可能会受到 与眼跳相关的独特形式的增益变化。这种可能性将是 检查LGN中代表中央区的细胞。为了更好地 理解指导LGN形态发生的发育规律，复合体 人体LGN的层叠图案将通过3-D可视化 对单个原子核的计算机重建以确定 恒河猴形态发生的计算模型 适用于人类。

Retinal signals are relayed to cerebral cortex through the lateral geniculate nucleus (LGN). The LGN is divided into several layers, in part segregating these signals by eye and functional class of retinal ganglion cell. In the cat, different layers also vary in the degree to which individual relay cells summate the output of multiple retinal cells, and thus the degree to which they gain sensitivity at the expense of spatial resolution. Long term objectives of this project are to understand how and why the LGN is organized into layers, what these channels contribute to perception and visuomotor behavior, how the information relayed through them is integrated in cerebral cortex, and how central feedback to the LGN dynamically regulates transmission of information to cortex. Contributions of individual layers to visuomotor behavior will be examined by briefly inactivating selected layers in cats carrying out oculomotor tasks. To test the hypothesis that LGN subdivisions vary in the degree to which they are specialized for high-acuity or high-sensitivity vision, inactivations will be done under conditions emphasizing the importance of either spatial resolution or dim-light vision. A similar paradigm will be used to test the hypothesis that the relative influence of different LGN layers on cortical activity varies depending on task demands and adaptations levels. Permanent lesions of dorsal LGN layers will be combined with reversible inactivations of central layers to examine the nature of a recovery of function that appears to occur that such lesions. This novel form of plasticity may shed light on perceptual deficits resulting from abnormalities in particular afferent saccadic eye movements. Because the purpose of saccades is to move the target of interest to central retina regions of the brain representing central retina might be subject to unique forms of saccade-elated changes in gain. This possibility will be examined for cells in the LGN representing the area centralis. To better understanding developmental rules guiding LGN morphogenesis, the complex lamination pattern of the human LGN will be visualized thorough 3-D computer reconstructions of individual nuclei to determine if a computational model of morphogenesis developed for the rhesus monkey can be applied to the human.