VERGENCE & OCULAR ACCOMMODATION--ROLE OF THE CEREBELLUM

每当凝视从远目标指向近目标时， 聚散和发散性眼球运动确保了融合的，良好的， 实现了聚焦图像。因此。 聚散度和适应度是 大多数眼球运动的基本组成部分。 不过虽然 眼睛对准障碍和调节功能障碍， 常见的临床眼科投诉，很少有人知道， 聚散和斜视眼的神经生理学基础 动作 虽然一些研究记录了运动或立即 中脑和顶盖前区的运动前神经元， 为这些细胞提供信息的人尚未被发现。 识别这些区域，以及聚散度和 住宿信号在其中处理，应该有助于我们 了解与近视相关的眼科投诉， 反应 我们对警觉灵长类动物的初步研究表明， 参与近响应的另一个区域是 小脑;特别是后间位核（PIN）。 因此，拟议的项目将调查PIN的作用 特别是小脑在控制聚散方面 和眼睛的运动。 单单位记录，病变， 微刺激和解剖技术将用于培训 猴子 眼球运动将被测量与搜索线圈 技术，将用红外线测量调节。 视力计和视觉刺激器将呈现目标， 独立的趋同性和自主性的要求。 具体地说， 将测试PIN近响应区域中的细胞， 决定了聚散度和适应度的各个方面， 有关系。 此外，他们将被测试，看看他们是否位于 在交叉耦合聚散度的链接之前和之后， 住宿系统。 近的功能意义- PIN的响应区域将使用以下任一项进行研究 可逆的利多卡因或不可逆的鹅膏蕈氨酸损伤。 的 投射到近反应的小脑皮层区域 PIN的区域将使用局部注射 WGA-HRP。 此外，使用微刺激，小脑将 调查以确定与聚合相关的其他区域，或 住宿. 更详细地了解中枢神经系统的这种性质， 处理聚散和发散性眼球运动应该有助于 在我们对斜视，双眼视觉障碍， 和排泄功能障碍

Whenever gaze is directed from a far target to a near target, vergence and accommodative eye movements ensure that a fused, well- focused image is achieved. Thus. vergence and accommodation are essential components of most eye movements. However, although disorders of ocular alignment and accommodation dysfunction are common clinical oculomotor complaints, little is known about the neurophysiological bases for vergence and accommodative eye movements. While a few studies have recorded motor or immediately premotor neurons in the midbrain and pretectum, the regions that provide inputs to these cells have not been identified. Identifying these regions, and the way in which vergence and accommodation signals are processed in them, should aid in our understanding of oculomotor complaints related to the near- response. Our preliminary studies in the alert primate have demonstrated that an additional region involved in the near-response is the cerebellum; specifically the posterior interpositus nucleus (PIN). The proposed project will therefore investigate the role of the PIN specifically, and the cerebellum in general in controlling vergence and accommodative eye movements. Single-units recording, lesion, microstimulation and anatomical techniques will be used in trained monkeys. Eye movements will be measured with the search coil technique, accommodation will be measured with an infrared optometer, and a visual stimulator will present targets with independent vergence and accommodative demands. Specifically, cells in the near-response region of the PIN will be tested to determine the aspects of vergence and accommodation that they are related to. Also, they will be tested to see if they are located before and after the links that cross-couple the vergence and accommodation systems. The functional significance of the near- response region of the PIN will be investigated using either reversible lidocaine or irreversible, ibotenic acid lesions. The regions of cerebellar cortex that project to the near-response region of the PIN will be identified using localized injections of WGA-HRP. Also, using microstimulation, the cerebellum will be surveyed to identify other regions related to vergence or accommodation. More detailed knowledge of this nature of the central neural processing of vergence and accommodative eye movements should aid in our understanding of strabismus, disorders of binocular vision, and accommodative dysfunction.