INFORMATION CHANNELS IN THE VESTIBULAR NERVE

拟议的研究涉及头部运动的控制， 前庭系统 这种运动在姿势方面起着重要作用。 反射和颅感觉器官的方向，但我们不知道 这些运动是如何在脑干和颈椎中组织起来的 线. 男性前庭颈功能障碍与 姿势调节缺陷，是临床常见的后遗症， 如梅尼埃病。 为了了解前庭对头部运动的控制，我们需要知道：（1） 前庭神经的功能成分，以及（2）这些是如何 与各种前庭神经元有关。 在 已经完成或正在进行的实验，我正在描述类 前庭脊髓神经元，它将信息传递到颈部运动场， 拟鼠 拟议的研究将扩展这种分析的头 肌肉控制 (1)前庭初级传入神经的外周轴突 用辣根过氧化物酶（HRP）标记，并根据 已知具有功能意义的4个形态学参数： 直径、终端类型、形态和在嵴上的位置。 （二） 将用光检查传入前庭初级毛细胞， 电子显微镜，和一个假设将被测试，涉及空间 已知生理差异的毛束结构变化 在初选之间。 (3)前庭初级毛的标记的中央轴突将 根据其直径、分枝模式和 与前庭核神经元的关系。 (4)定量技术将 用于基于它们的分类来识别外周和中央轴突的类别。 形态，传入和中央目标，并确定可能的 外周与中央轴突类的配对。 这些目标 实验是为了确定各种形态的人口 前庭初级传入，并帮助了解功能作用 每一个都参与了头部运动的组织。 这项研究，结合 将有助于我们对运动的理解 以两种方式控制。 这项研究将是第一个 信息通道的全面、系统的形态描述 在任何脊椎动物的前庭神经中。 因此，它将有助于 前庭信息处理的一般理解。 二是 拟议中的研究将提供有关 轴向电机系统的下降控制。

The proposed research deals with the control of head movements by the vestibular system. Such movements play an important role in postural reflexes and the orientation of cranial sense organs, but we do not know how these movements are organized within the brainstem and cervical spinal cord. Abnormalities in vestibulocollic function in man are associated with deficits in postural regulation and are common sequelae of clinical conditions such as Meniere's disease. To understand vestibular control of head movements we need to know: (1) the functional components of the vestibular nerve, and (2) how these are related to the various classes of vestibulocervical neurons. In experiments already completed or underway I am characterizing the classes of vestibulospinal neurons which relay information to neck motorpools in Pseudemys scripta. The proposed research will extend this analysis of head muscle control. (1) Peripheral axons of vestibular primary afferents will be labelled with horseradish peroxidase (HRP) and characterized in terms of 4 morphological parameters that are known to have functional significance: diameter, and terminal type, morphology, and location on the crista. (2) Hair cells afferent to vestibular primaries will be examined with light and electronmicroscopy, and an hypothesis will be tested that relates spatial variation in hair bundle structure to known physiological differences between primaries. (3) Labelled central axons of vestibular primaries will be characterized in terms of their diameter, branching pattern and relations to vestibular nucleus neurons. (4) Quantitative techniques will be used to identify classes of peripheral and central axons based on their morphologies, afferents, and central targets, and to determine probable pairings of peripheral with central axon classes. The object of these experiments is to identify the various morphological population of vestibular primary afferents and to help understand the functional role each plays in the organization of head movements. This research, combined with work in progress, will contribute to our understanding of movement control in two ways. The proposed research will constitute the first comprehensive, systematic morphological description of information channels in the vestibular nerve of any vertebrate. Thus it will contribute to a general understanding of vestibular information processing. Second, the proposed research will provide important data on mechanisms underlying the descending control of axial motor systems.