Neural organization of eye movements in depth

描述（由申请人提供）：通常需要双眼旋转不同程度的解共轭动眼肌反应。赫林等神经支配定律指出有两组动眼肌指令。共轭命令使眼睛在相同的方向上旋转相同的数量，类似于一对双眼皮。会聚命令通过在相反的方向上以相同的幅度旋转眼睛来控制眼睛之间的角度。任何非共轭眼旋转都可以通过适当的共轭和收敛命令得到。最近的证据表明，一些解耦反应可能是由独立的左眼和右眼非对称指令驱动的，可能直接到达趋同通路外的运动神经元。这些假定的单眼信号在功能上是否重要？我们将通过估计由收敛系统直接在神经元水平上编码的解共轭命令的百分比来解决这个问题。如果赫林定律是正确的，收敛系统必须解释整个解共轭反应，而不依赖于刺激的类型或产生它的动眼肌系统。这些估计将在以下过程中完成：1)在静止目标之间的深度注视自主转移；2)自主平滑跟踪深度运动的小物体；3)超短潜伏期反射性视觉稳定反应；4)线性前庭-眼反应。单单元记录的神经目标将是中脑中的收敛相关细胞。双眼水平、垂直和扭转眼球运动将与这些细胞的神经活动一起被记录下来。高场解剖和功能MRI将有助于定位这些区域。复视导致视觉功能严重退化。至少有4%的美国人长期双眼排列缺陷，如斜视和弱视。了解解耦指令是如何产生并传递到眼外肌的，对于制定影响双眼对齐的动眼肌疾病的正确临床管理至关重要，无论是诊断动眼肌缺陷的来源，还是选择适当的手术或光学干预措施。这些机制的神经基础知识将是理解眼球运动适应过程的关键工具，帮助患者重新校准他/她的眼球运动命令，以恢复或至少部分改善双目视力，这是人们知之甚少的。

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.