Vestibular Influences on Head Direction Cell Activity

前庭对头部方向细胞活动的影响

• 批准号: 6736307
• 负责人: BILL J YATES
• 金额: $ 14.85万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6736307
• 关键词: biological signal transduction; cell type; electrodes; electrophysiology; head; head movements; hippocampus; hypothalamus; laboratory rat; mature animal; neuronal transport; proprioception /kinesthesia; suid alphaherpesvirus 1; synapses; thalamus; vestibular nuclei; vestibular pathway

DESCRIPTION (provided by applicant): Head direction cells (HDC) located in several regions of the brain, including the anterior dorsal nucleus of the thalamus, postsubiculum, and lateral mammillary nuclei, provide the neural substrate for the determination of directional heading. Although activity of HDC is influenced by various sensory signals and internally generated cues, lesion studies and some anatomical and physiological evidence suggest that vestibular inputs are critical for the maintenance of directional sensitivity of these cells. In addition, relatively direct pathways have been proposed that could relay vestibular signals to brain areas containing HDC. However, vestibular inputs must be transformed considerably in order to signal head direction, and it is uncertain whether the simple circuitry that has been postulated to mediate vestibular influences on HDC can accomplish this transformation of signals. One purpose of the proposed research is to establish whether a relatively direct pathway links the vestibular nuclei with brain areas containing HDC. Specific Aim 1 tests the hypothesis that injection of the retrograde transneuronal tracer pseudorabies virus into two areas containing HDC, the anterior dorsal nucleus of the thalamus and lateral mammillary nuclei, results in labeling of neurons in the vestibular nuclei within short survival times, suggesting that only a few synapses separate HDC from vestibular nucleus neurons. Furthermore, definitive physiological studies have not been conducted to determine whether HDC respond similarly during active head rotations and passive rotations of the animal's body that activate labyrinthine receptors. If labyrinthine signals contribute to the directional sensitivity of HDC as substantially as suggested by prior lesion studies, then these cells should respond to high-frequency passive horizontal rotations that powerfully activate semicircular canal afferents. Specific Aim 2 tests the hypothesis that HDC have similar responses to active head rotations in the horizontal plane and passive rotations imposed using a turntable, including rotations delivered in the dark such that the predominant sensory information available is from the labyrinth. These experiments will establish whether the vestibular system plays a direct and powerful role in determining directional heading, and should advance understanding of the neural underpinnings of navigation. This work may also provide insights into potential effects of peripheral and central vestibular lesions on spatial cognition in humans.

描述（由申请人提供）：头部方向细胞（HDC）位于大脑的几个区域，包括丘脑前背核、下托后核和乳头体外侧核，为确定方向性航向提供神经基质。虽然HDC的活动受到各种感觉信号和内部产生的线索的影响，但病变研究和一些解剖学和生理学证据表明，前庭输入对于维持这些细胞的方向敏感性至关重要。此外，已经提出了相对直接的途径，可以将前庭信号传递到含有HDC的脑区。然而，前庭输入必须进行相当大的转换，以信号头的方向，它是不确定的简单的电路，已被假定为介导前庭对HDC的影响，可以完成这种信号的转换。这项研究的目的之一是确定是否有一个相对直接的通路将前庭核与含有HDC的大脑区域联系起来。具体目标1测试的假设，逆行transneuronal示踪剂伪狂犬病病毒注射到两个地区含有HDC，丘脑和外侧乳头核的前背核，结果在前庭核神经元的标记在短的生存时间内，这表明只有少数突触分离HDC前庭核神经元。此外，尚未进行明确的生理学研究来确定HDC在激活谷胱甘肽受体的动物身体的主动头部旋转和被动旋转期间是否类似地响应。如果HDC的方向敏感性与先前的损伤研究所提出的基本相同，那么这些细胞应该对高频被动水平旋转做出反应，从而有力地激活半规管传入。特定目标2测试了这样的假设：HDC对水平面上的主动头部旋转和使用转盘施加的被动旋转具有相似的反应，包括在黑暗中传递的旋转，使得可用的主要感觉信息来自迷宫。这些实验将确定前庭系统是否在确定方向方面发挥直接而强大的作用，并且应该促进对导航神经基础的理解。这项工作也可能提供洞察周围和中央前庭病变对人类空间认知的潜在影响。