Role of Parabigeminal Neucleus in Visuomotor Behavior

副二叉神经核在视觉运动行为中的作用

• 批准号: 6725929
• 负责人: JOSEPH G MALPELI
• 金额: $ 36.18万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6725929
• 关键词: behavioral /social science research tag; cats; electrodes; mesencephalon; motion perception; oculomotor nuclei; olivary body; saccades; single cell analysis; smooth pursuit eye movement; superior colliculus; trigeminal nerve; visual feedback; visual fixation; visual stimulus; visual tracking

DESCRIPTION (provided by applicant): Good vision requires an oculomotor system that can make rapid and accurate eye movements, called saccades, to visual targets of interest. To do this, the brain must have an internal representation of target location. The superior colliculus (SC), the main source of saccade commands to brainstem circuits driving the eyes, encodes target localization and saccade metrics by place codes: a retinotopic map of locations in register with a map of saccade vectors. It appears that the parabigeminal nucleus (PBN), a small cluster of cells on the lateral edge of the midbrain that is reciprocally interconnected with the SC, also encodes target location, but by a rate code. When cats visually track a moving object, they rely primarily on a series of catch-up saccades to continually intercept it. Preliminary studies have revealed that in the intervals between catch-up saccades, PBN cells fire at rates proportional to the distance between the eye and potential target, or retinal position error (RPE). During saccades, PBN activity abruptly changes to levels appropriate to RPE at saccade end in a fashion that seems too fast for visual feedback, suggesting that activity may be reset by an internally generated signal, such as a resettable integrator of eye velocity, or an open-loop feedforward signal. Its robust anatomical interconnections with the SC imply that the PBN primarily contributes to the saccade system by providing continuous information on target location during intersaccade intervals. Whether or not it contributes to the dynamics or metrics of the saccade is unknown. Since the SC place code must at some point be translated into a rate code to drive eye movements, the PBN may provide a useful model for understanding how a place-to-rate code translation can be accomplished. The goals of this project include better defining the range and topography of RPE encoding, determining if PBN activity provides an index of the currently attended saccade target, examining PBN interactions with the SC, investigating the nature of the signal that resets PBN activity during saccades, and examining the role of the PBN in predictive tracking of moving targets. Historically, there has been a productive interaction between oculomotor physiology and clinical neurology. The PBN appears to be an important part of the oculomotor system, and its incorporation into models of oculomotor circuits will extend this valuable interchange.

描述（由申请人提供）：良好的视力需要一个眼科系统，可以快速和准确的眼球运动，称为扫视，视觉目标的兴趣。要做到这一点，大脑必须对目标位置有一个内部表征。上级丘（SC）是驱动眼睛的脑干回路的扫视命令的主要来源，其通过位置代码对目标定位和扫视度量进行编码：与扫视向量的地图配准的位置的视网膜位置图。似乎二叠旁核（PBN），一个位于中脑外侧边缘的小簇细胞，与SC相互连接，也编码目标位置，但通过速率代码。当猫在视觉上跟踪一个移动的物体时，它们主要依靠一系列的追赶扫视来持续拦截它。初步研究表明，在追赶扫视之间的间隔中，PBN细胞的放电率与眼睛和潜在目标之间的距离成正比，或视网膜位置误差（RPE）。在扫视过程中，PBN活动突然改变到水平适当的RPE在扫视结束的方式，似乎太快的视觉反馈，这表明活动可能会被重置的内部产生的信号，如可重置的积分器的眼速度，或开环前馈信号。其强大的解剖学互连与SC意味着PBN主要有助于眼跳系统提供连续的信息，在目标位置的眼跳间隔。它是否有助于扫视的动力学或度量是未知的。由于SC位置代码必须在某个点处被转换成速率代码以驱动眼球运动，因此PBN可以提供用于理解如何能够完成位置到速率代码转换的有用模型。该项目的目标包括更好地定义RPE编码的范围和地形，确定PBN活动是否提供了当前参加的扫视目标的指数，检查PBN与SC的相互作用，调查扫视期间重置PBN活动的信号的性质，并检查PBN在预测跟踪移动目标中的作用。从历史上看，眼科生理学和临床神经学之间一直存在着富有成效的相互作用。PBN似乎是眼神经系统的一个重要组成部分，将其纳入眼神经回路模型将扩展这种有价值的交换。