Corticotectal transmission for express saccades

描述(由申请人提供)：灵长类动眼系统是理解反射性和意志性运动产生的主要模型系统。人类和猴子的眼跳动作有两种：“常规”眼跳和“快速”眼跳。规则的眼跳潜伏期很长，被认为涉及到信息从视觉皮质到额叶皮质和上丘的传输。快速眼跳的潜伏期较短，被认为是通过一条从视觉皮质到上丘的直接通路，绕过额叶皮质来调节的。重要的是，在某些情况下，快速扫视和常规扫视的比例大致相同；在一些试验中出现快速扫视，在其他看似相同的试验中出现常规扫视。如果像假设的那样，快速眼跳是通过从视觉皮质到上丘的投射来调节的，如果这些投射是在不是自然强烈激活的条件下刺激的，那么发生快速眼跳的可能性应该会增加。直到最近，这样的操作在技术上还是不可能的，但光遗传学改变了这一点。光遗传学是一套相对较新的用光来操纵神经活动的工具，这些工具在转基因小鼠的研究中已经非常有价值。通过在清醒的灵长类动物中使用这些工具，将实现两个特定的目标和一个更广泛的目标。第一个目的是测试从视觉皮质到上丘的投射促进快速眼跳的假设。第二个目的是验证这样一种假设，即在快速眼跳过程中，上丘两个通常不相连的隔室之间的电活动会瞬间连接起来。更大的目标是通过改进光遗传工具来催化系统神经生理学的进步，以用于清醒的、行为正常的猴子。灵长类神经生理学社区对这些技术的广泛采用和改进将有助于揭示大脑区域之间的信号传输如何调节行为。这种理解对于神经和精神疾病的诊断和治疗将是重要的，这些疾病的病因可能涉及大脑区域之间的异常交流。

DESCRIPTION (provided by applicant): The primate oculomotor system is a premier model system for understanding the production of reflexive and volitional movements. Two types of saccadic eye movements are made by humans and monkeys: "regular" and "express" saccades. Regular saccades have long latencies and are thought to involve the transfer of information from the visual cortex, to the frontal cortex, to the superior colliculus. Express saccades have shorter latencies and are thought to be mediated by a direct pathway from visual cortex to the superior colliculus, bypassing the frontal cortex. Importantly, under some conditions both express and regular saccades are made in roughly equal proportion; express saccades occur on some trials, regular saccades on other, seemingly identical, trials. If, as hypothesized, express saccades are mediated by projections from the visual cortex to the superior colliculus, the probability of express saccade occurrence should increase if these projections are stimulated under conditions in which they are not naturally strongly activated. Such a manipulation was technically impossible until recently, but optogenetics has changed this. Optogenetics is a relatively new set of tools for manipulating neural activity with light, an these tools have already been extremely valuable in the study of transgenic mice. By using these tools in the awake, behaving primate, two specific aims and one broader objective will be achieved. The first aim is to test the hypothesis that the projections from visual cortex to the superior colliculus facilitate express saccades. The second aim is to test the hypothesis that electrical activity between two usually disconnected compartments in the superior colliculus become transiently connected during express saccades. The larger objective is to catalyze progress in systems neurophysiology by refining optogenetic tools for use in the awake, behaving monkey. Widespread adoption and refinement of these techniques by the primate neurophysiology community will help to reveal how signal transmission between brain areas mediates behavior. Such an understanding will be important for the diagnosis and treatment of neurological and psychiatric diseases, whose etiology may involve aberrant communication between brain areas.