Spatial Interaction of Otolith mediated Collic Reflexes

耳石介导的绞痛反射的空间相互作用

• 批准号: 7418261
• 负责人: Greg Thomas Gdowski
• 金额: $ 22.7万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7418261
• 关键词: 3-Dimensional; Acceleration; Address; Affect; Animals; Cell Nucleus; Cells; Cervical; Cervical spinal cord injury; Condition; Data; Doctor of Medicine; Doctor of Philosophy; Electric Stimulation; Electromyography; Elevation; Equipment; Exhibits; Gait; Head; Head Movements; Life; Locomotion; Mediating; Motor; Movement; Muscle; Neck; Neurons; Optics; Pathway interactions; Pattern; Physiological; Population; Positioning Attribute; Posture; Primates; Principal Investigator; Property; Published Comment; Reflex action; Reflex control; Relative (related person); Research; Rotation; Saimiri; Signal Transduction; Skeletal muscle structure of neck; Stimulus; Techniques; Technology; Testing; Thinking; Translating; Translations; Vestibular nucleus structure; Yaws; base; gaze; otoconia; programs; receptor; relating to nervous system; research study; response; vector

Project 2, Spatial interactions of otolith mediated collic reflexes (Gdowski, PI), asks how the vestibular signals arising from otolith endorgans, which detect horizontal and vertical acceleration, are used to activate neck muscles that reflexively reorient the head. Cervical injury affects 1 million U.S. lives annually, yet we are just beginning to understand how postural reflexes that evolved to protect the neck are controlled. Progress has been hampered, in part, because of the complexity of the neck musculature and its multiple functions in reorienting gaze and reflexively stabilizing the head with respect to the body. Vestibulospinal (VS) pathways are richly innervated by converging otolith inputs. The signals carried by the VS pathways bilaterally and reciprocally activate neck muscles during static tilts and linear translations of the body. We hypothesize that neck muscle activity will exhibit spatial tuning when combinations of tilt and translation are imposed on the body sequentially throughout 3-D space. We further hypothesize that the spatial tuning of neck muscles is causally related to the spatial tuning of responses of vestibulospinal neurons. To test these hypotheses experiments will be carried out in squirrel monkeys in which the electromyography (EMG) of neck muscles and neural activity of VS pathways are recorded. Different combinations of tilt and translation will be imposed on the body throughout 3-D space. Initial experiments will determine if specific groups of neck muscles exhibit spatial tuning during tilts and translations in different directions. The second set of experiments will determine if VS neurons, recorded in the vestibular nuclei, exhibit spatial tuned responses during tilts and translations in different directions. VS neurons will be identified physiologically by antidromic stimulation. In addition, neck EMG activity and VS neuron activity will be recorded simultaneously so that spike-triggered averaging (SpikeTA) can be used to identify functional relationships between neural discharge and EMG activity. The spatial tuning of each neck muscle will be compared to the collective spatial tuning properties of sub-populations of VS neurons identified as functionally-related to the neck muscle (identified through SpikeTA). This analysis will be used to determine if the spatially-tuned neck EMG activity are causally related to the spatial properties of VS pathways. In the final experiments, the head will be allowed to move in the direction of translation while the responses of VS neurons are recorded. The directions of translation will be chosen based upon direction that maximally activates the neuron. These data will used us to determine how otolith signals are modified during the execution of collic reflexes. The results of these experiments are significant to our understanding of how otolith signals influence the orientation of the head during normal activities such as locomotion.

项目 2，耳石介导的结肠反射的空间相互作用（Gdowski，PI）询问如何使用耳石内器官产生的前庭信号（检测水平和垂直加速度）来激活颈部肌肉，从而反射性地重新定向头部。宫颈损伤每年影响 100 万人的生命，但我们才刚刚开始了解如何控制为保护颈部而进化的姿势反射。进展受到阻碍，部分原因是颈部肌肉组织的复杂性及其在重新定向视线和反射性地稳定头部相对于身体的多重功能。前庭脊髓 (VS) 通路受到会聚耳石输入的丰富神经支配。 VS 通路携带的信号 在身体静态倾斜和线性平移期间双边和相互激活颈部肌肉。我们假设，当在整个 3D 空间中顺序地将倾斜和平移组合施加于身体时，颈部肌肉活动将表现出空间调谐。我们进一步假设颈部肌肉的空间调节与前庭脊髓神经元反应的空间调节存在因果关系。为了检验这些假设，我们将在松鼠猴中进行实验，记录颈部肌肉的肌电图 (EMG) 和 VS 通路的神经活动。倾斜和平移的不同组合将在整个 3D 空间中施加到身体上。初步实验将确定特定的颈部肌肉群在不同方向的倾斜和平移过程中是否表现出空间调谐。第二组 实验将确定前庭核中记录的 VS 神经元在不同方向的倾斜和平移过程中是否表现出空间调谐反应。 VS 神经元将通过逆向刺激在生理上被识别。此外，颈部 EMG 活动和 VS 神经元活动将被同时记录，以便尖峰触发平均 (SpikeTA) 可用于识别神经放电和 EMG 活动之间的功能关系。每个颈部肌肉的空间调谐将与被识别为与颈部肌肉功能相关的 VS 神经元亚群的集体空间调谐特性（通过 SpikeTA 识别）进行比较。该分析将用于确定空间调整的颈部肌电图活动是否与 VS 通路的空间特性存在因果关系。在最终实验中，头部将被允许沿平移方向移动，同时记录 VS 神经元的反应。平移方向将根据最大限度地激活神经元的方向来选择。这些数据将用于确定耳石信号在结肠反射执行过程中如何被修改。这些实验的结果对于我们理解耳石信号如何影响正常活动（例如运动）期间头部的方向具有重要意义。