Neural organization of eye movements in depth

深度眼球运动的神经组织

• 批准号: 7073555
• 负责人: CLAUDIO BUSETTINI
• 金额: $ 20万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-30 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7073555
• 关键词: eye; eye movements; mesencephalon; motivation; motor neurons; saccades

DESCRIPTION (provided by applicant): Disconjugate oculomotor responses, where the two eyes rotate by different amounts, are often needed. Hering's law of equal innervation states that there are two groups of oculomotor commands. Conjugate commands rotate the eyes in the same amount in the same direction similarly to a yoked pair. Vergence commands control the angle between the eyes by rotating the eyes in same amount in the opposite direction. Any disconjugate eye rotation can be obtained by appropriate conjugate and vergence commands. Recent evidence shows that some disconjugate responses may be driven by independent left- and right-eye asymmetric commands, perhaps directly reaching the motor neurons outside the vergence pathway. Are these putative monocular signals functionally significant? We will address this question by estimating the percentage of disconjugate command encoded by the vergence system directly at the neuronal level. If Hering's law is correct, the vergence system must account for the entire disconjugate response, independently of the type of stimulus or the oculomotor system in which it was generated. These estimates will be done during: 1) voluntary transfers of gaze in depth between stationary targets; 2) voluntary smooth tracking of small objects moving in depth; 3) ultra-short latency reflexive visual stabilization responses; and 4) linear vestibulo-ocular responses. Neural targets for the single-unit recordings will be the vergence-related cells in midbrain. Binocular horizontal, vertical, and torsional eye movements will be recorded together with the neural activity of these cells. High-field anatomical and functional MRI will help localize these areas. Visual function is severely degraded by double vision. At least 4% of the US population is affected by long- term deficits in binocular alignment, such as strabismus and amblyopia. The understanding of how disconjugate commands are generated and delivered to the extraocular muscles is of critical importance in developing a correct clinical management of oculomotor disorders affecting binocular alignment, both as diagnosis of the source of the oculomotor deficit and the selection of the proper surgical or optical intervention. Knowledge of the neural substrate of these mechanisms will be a crucial tool in the understanding of the oculomotor adaptive processes that help a patient recalibrate his/her eye movement commands to regain, or at least partially improve, binocularity, which are poorly understood.

描述（由申请人提供）：通常需要双眼旋转不同量的非共轭眼球反应。赫林的平等神经支配定律指出，有两组眼神经指令。共轭命令在相同的方向上以相同的量旋转眼睛，类似于一对轭。聚散度命令通过在相反方向上以相同的量旋转眼睛来控制眼睛之间的角度。任何非共辄眼睛旋转可以通过适当的共辄和聚散命令来获得。最近的证据表明，一些非共轭反应可能是由独立的左眼和右眼不对称的命令，也许直接到达运动神经元的聚散路径以外。这些假定的单眼信号在功能上重要吗？我们将解决这个问题，估计的百分比，直接在神经元水平上的聚散系统编码的非共轭命令。如果赫林定律是正确的，则聚散系统必须解释整个非共轭反应，而与刺激的类型或产生它的眼神经系统无关。这些估计将在以下期间进行：1）静止目标之间的深度凝视的自愿转移; 2）在深度移动的小物体的自愿平滑跟踪; 3）超短潜伏期反射性视觉稳定响应;以及4）线性前庭眼响应。单单位记录的神经靶点将是中脑中的聚散相关细胞。将记录双眼水平、垂直和扭转眼球运动以及这些细胞的神经活动。高场解剖和功能MRI将有助于定位这些区域。复视会严重损害视觉功能。至少有4%的美国人口受到双眼对准长期缺陷的影响，如斜视和弱视。解共轭命令是如何产生和传递到眼外肌的理解是至关重要的，在发展一个正确的临床管理影响双眼对准的眼病，无论是作为诊断的眼病缺陷的来源和选择适当的手术或光学干预。这些机制的神经基质的知识将是一个至关重要的工具，在理解的眼自适应过程，帮助患者重新校准他/她的眼球运动命令，以恢复，或至少部分地改善，双眼，这是知之甚少。