Vestibular Influences on Head Direction Cell Activity

前庭对头部方向细胞活动的影响

• 批准号: 6614167
• 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 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6614167
• 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）：位于大脑多个区域的头部方向细胞（HDC），包括丘脑的前背核，临时学和乳头侧核，为确定方向头的确定提供了神经底物。尽管HDC的活性受各种感觉信号和内部提示的影响，但病变研究和一些解剖学和生理证据表明，前庭输入对于维持这些细胞方向敏感性至关重要。此外，已经提出了相对直接的途径，该途径可以将前庭信号转移到含有HDC的大脑区域。但是，必须对前庭输入进行大量转换才能发出信号方向，并且不确定已经假定介导前庭影响HDC的简单电路是否可以实现这一信号的转换。拟议研究的目的之一是确定相对直接的途径是否将前庭核与含有HDC的大脑区域联系起来。具体目的1检验了以下假说：逆行透射式示踪剂伪标记病毒进入含有HDC的两个区域，这些区域是HDC，丘脑的前背核和乳房乳房核心的外侧髓核，导致在短期存活时间内的神经元标记的神经元标记，暗示了一个Sync sync sync sync sync sync sync。此外，尚未进行确定的确定生理研究以确定在激活迷宫受体的动物体内的主动头部旋转和被动旋转过程中是否相似的响应。如果迷宫信号正如先前的病变研究所建议的那样有助于HDC的方向灵敏度，那么这些细胞应应对高频被动水平旋转，以有力激活半圆形管传入。特定的目标2检验了HDC对使用转盘施加的水平平面和被动旋转的主动头部旋转的假设，包括在黑暗中传递的旋转，因此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标题中起着直接而有力的作用，并应提高对导航神经基础的理解。这项工作还可以提供有关外围和中央前庭病变对人类空间认知的潜在影响的见解。