Neural control of coordinated eye movements

协调眼球运动的神经控制

• 批准号: 10475578
• 负责人: Julie Quinet
• 金额: $ 36.01万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10475578
• 关键词: 3-Dimensional; Anatomy; Animals; Area; Brain region; Cell Nucleus; Cells; Cerebellar Nuclei; Cerebellum; Code; Complex; Contralateral; Convergence Insufficiency; Data; Electrophysiology (science); Elements; Environment; Eye; Eye Movements; Functional disorder; Generations; Goals; Impairment; Individual; Injections; Lateral; Lead; Maintenance; Medial; Modeling; Motor Neurons; Movement; Muscimol; Neurons; Nucleus fastigii; Oculomotor nucleus; Pathway interactions; Pharmacology; Play; Population; Positioning Attribute; Primates; Production; Reticular Formation; Role; Route; Saccades; Signal Transduction; Strabismus; Techniques; Testing; Time; Visual; abducens nucleus; base; cell type; disability; electrical microstimulation; experimental study; gaze; insight; interest; monocular; neural circuit; neural model; neurophysiology; neuroregulation; novel; oculomotor; relating to nervous system; response; sample fixation; targeted imaging

Project Summary / Abstract We look between targets located in the 3D visual environment by making disjunctive saccades that bring the target image onto both foveae. Each gaze shift is followed by a fixation period for visual analysis during which the new vergence level must be maintained. Most studies have focused on the circuitry controlling conjugate saccades, whereas the neural control of disjunctive saccades and vergence eye movements has received less study. Several models suggest that abducens motoneurons send a monocular command carrying information to each eye to control disjunctive saccades. Other models have proposed the existence of saccade-vergence burst neurons (SVBNs) that project to medial rectus motoneurons and are active only during disjunctive saccades. We have identified this novel cell type, which only discharge during disjunctive saccades, in the central mesencephalic reticular formation (cMRF) lateral to the oculomotor nucleus (OMN). Electrical microstimulation in this region of the cMRF elicits disjunctive saccades, whereas inactivation impairs vergence gaze holding. Recent anatomical findings have demonstrated that premotor neurons related to the near response are located in the cMRF, and that they project to the supraoculomotor area (SOA) and to the OMN. We hypothesize that the cMRF, and the SVBNs in particular, play a critical role in the generation of disjunctive saccades. We further hypothesize that projections between the cMRF and SOA form part of a previously undescribed neural circuit that produces vergence integration, allowing vergence angle to be maintained during fixation. Other anatomical and electrophysiological findings demonstrate that the cerebellum, specifically, the caudal fastigial nucleus and the posterior interposed nucleus, play a role in controlling vergence eye movements in both normal and strabismic individuals. We therefore hypothesize that the cerebellar input to the cMRF/SOA complex helps encode or modulate disjunctive saccades. Guided by these overarching hypotheses, we propose Specific Aims to characterize this neural circuitry. 1. To determine the role of SVBNs and the cMRF in the production of disjunctive saccades; 2. To test the hypothesis that the cMRF/SOA complex is the vergence integrator responsible for maintaining the level of convergence; 3. To determine how the cerebellar projections to the cMRF/SOA circuitry are involved in the generation of disjunctive saccades and vergence eye movements. To test our specific hypotheses, we will use established neurophysiological techniques (electrophysiological recordings, antidromic activation, electrical microstimulation and reversible pharmacological modulation). The overall goal of our project is to substantially increase our understanding of the neural circuitry controlling 3D eye movements in primates, and to broadly impact the oculomotor field, leading to new neurophysiological and modeling approaches. These findings will also provide a critical basis for understanding the absence of precise binocular coordination in eye movement dysfunctions such as strabismus.

项目摘要 /摘要 我们通过制作脱节的扫视来探视位于3D视觉环境中的目标 目标图像在两个foveae上。每个目光转移之后都有一个视觉分析的固定期，在此期间 必须维持新的gergence级别。大多数研究都集中在控制共轭的电路上 扫视，而脱节性扫视和Gergence眼动的神经控制却较少 学习。几种型号表明，被外套的运动神经元发送了一个单眼命令，该命令载有信息 每只眼睛控制分离的扫视。其他模型提出了扫视 - 佛罗斯的存在 神经元（SVBN）将内侧直肠运动神经元投射，并且仅在分离性扫视过程中活跃。我们 已经确定了这种新颖的细胞类型，仅在中央排出的扫视过程中排出 脑脑性网状形成（CMRF）向眼核（OMN）的侧面。电微刺激 在CMRF的这一区域中，引发了分离的扫视，而灭活会损害凝视的凝视。 最近的解剖学发现表明，与近反应有关的前神经元位于 在CMRF中，他们将其投射到上型群体（SOA）和OMN。我们假设 CMRF，尤其是SVBN，在分离扫视的产生中起着至关重要的作用。我们进一步 假设CMRF和SOA之间的投影构成了先前未描述的神经回路的一部分 这会产生Gergence的整合，从而使固定过程中保持捕捉角度。其他解剖学 电生理发现表明，小脑特别是尾核核和 后置核核，在控制正常和 斜视的个体。因此，我们假设CMRF/SOA复合体的小脑输入有助于 编码或调节分离的扫视。在这些总体假设的指导下，我们提出了具体目标 表征该神经电路。 1。确定SVBN和CMRF在生产中的作用 分离的扫视； 2。检验CMRF/SOA复合物是Gergence积分器的假设 负责维持收敛水平； 3。确定小脑预测如何 CMRF/SOA电路参与了分离的扫视和Gergence Eye的产生 动作。为了检验我们的特定假设，我们将使用已建立的神经生理技术 （电生理记录，抗体激活，电微刺激和可逆的 药理调节）。我们项目的总体目标是实质上提高我们对 控制灵长类动物中的3D眼动的神经电路，并广泛影响眼球场。 新的神经生理和建模方法。这些发现还将为 了解眼睛运动功能障碍（如斜视）中缺乏精确的双眼协调。