PROCESSING OF BILATERAL INPUTS TO VESTIBULAR NUCLEUS

描述：(改编自《调查者摘要》)这是一个修订版 描述使用体外实验的新实验的申请(R01 03894-01a) 附着性颞骨的脑准备研究初始前庭 脊椎动物脑干的加工。最初的首席调查员 开发了这些创新技术来研究反射路径的视觉输入 以稳定视网膜图像。在这项拨款申请中，只有磁头旋转 我们将研究前庭核团的反应。全细胞贴片记录 其中的这些反应将在单边可逆之前和之后进行检查 利多卡因第八神经失活。 同侧单突触兴奋性神经管传入纤维汇聚至神经元 前庭核团。多突触输入也被认为达到了同样的水平 来自对侧神经管的神经元具有相应的旋转轴。 在自然状态下，前庭核神经元也表现出几种反应类型 头部水平旋转。细胞对运动到或离开侧面做出反应 录音和它们的尖峰放电可以编码磁头的速度或 加速。为了阐明前庭潜在的神经回路 核，来自第八神经传入和两个核之间， 单个突触事件的高分辨率贴片记录将被制作为 头部旋转和电神经刺激引起兴奋性和/或 抑制通路。应用突触药物的效果将有助于识别 神经递质参与单突触和多突触回路。 前庭核细胞的膜特性将被分析以了解 他们如何修改这些突触输入以产生不同的尖峰输出 前庭反应类型。 来自两个迷宫的多余感觉输入对改善前庭很有用 敏感性和单边损失的补偿。该项目分析 这些双边投入以了解它们在自然环境中的作用 产生一种正常的平衡感或产生 在病理性状态下出现眩晕。

DESCRIPTION: (Adapted from the Investigator's Abstract) This is a revised application (R01 03894-01A) that describes novel experiments using an in vitro brain preparation with attached temporal bones to study the initial vestibular processing of the vertebrate brainstem. The Principal Investigator initially developed these innovating techniques to study visual inputs to reflex paths that stabilize the retinal image. In this grant application, only head rotation responses will be studied in the vestibular nuclei. Whole-cell patch recordings of these responses will be examined before and after unilateral reversible lidocaine inactivation of the eighth nerve. Ipsilateral monosynaptic excitatory canal afferents converge onto neurons in the vestibular nucleus. A polysynaptic input is also thought to reach the same neurons from a contralateral canal with the corresponding axis of rotation. Vestibular nucleus neurons also display several response types during natural horizontal head rotation. Cells respond to motion to or away from the side of the recording, and their spike discharges can encode the head's velocity or acceleration. To elucidate the underlying neural circuitry of the vestibular nuclei, from the eighth nerve afferents and between the two nuclei, high-resolution patch recordings of individual synaptic events will be made as head rotation and electrical nerve stimulation evoke the excitatory and/or inhibitory pathways. Effects of synaptic drug applications will help identify the neurotransmitters involved in the monosynaptic and polysynaptic circuits. The membrane properties of the vestibular nucleus cells will be analyzed to see how they modify those synaptic inputs to yield the spike output of different vestibular response types. Redundant sensory input from both labyrinths is useful to improve vestibular sensitivity and to compensate for a unilateral loss. This project analyzes these bilateral inputs to gain an understanding of their role in the natural processing that results in a normal sense of balance or produces the feeling of vertigo during a pathological condition.