Vestibulo-spinal influences on reflex performance

前庭脊髓对反射性能的影响

• 批准号: 7105468
• 负责人: Greg Thomas Gdowski
• 金额: $ 34.6万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-19 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7105468
• 关键词: Saimiri; behavior test; biological signal transduction; biomechanics; body movement; electrodes; electromyography; eye movements; head movements; neural information processing; neurons; neurophysiology; oculomotor nuclei; posture; proprioception /kinesthesia; sensorimotor system; spinal cord; spinal reflex; vestibuloocular reflex; visual fixation; visual stimulus

DESCRIPTION (provided by applicant): Postural reflexes are evoked and controlled by a variety of sensory inputs. The vestibulo-spinal (VS) pathways carry sensory vestibular signals to widespread regions of the spinal cord where they interact with motor nuclei to produce reflexive movement. The vestibulo-collic reflexes (VCR) are an important subset of postural reflexes that avert potential neck injury by reorienting the head during perturbations of the body. The neck motor nuclei involved in producing the VCR receive input from two distinct populations of VS neurons that are anatomically distinguished by the absence or presence of collateral projections to the oculomotor nucleus. We hypothesize that these two distinct VS populations are important in controlling both reflexive head movements and reflexive gaze shifts (combined eye and head). To test this hypothesis we will record the firing behavior of VS neurons located in the vestibular nuclei during reflexive, voluntary, and passive head movements in the awake squirrel monkey. The monkey will be seated on a vestibular turntable and will be permitted to produce different combinations of voluntary and reflexive head movements only in the plane of the horizontal semicircular canals. Responses during voluntary and reflexive head movements will be quantified with respect to the response during rotations when the head is not permitted to move with respect to the body. Secondary VS neurons will be orthodromically identified from the vestibular nerve and antidromically identified as projecting to the spinal cord. VS neurons projecting to the oculomotor nucleus will be identified by the presence of eye movement related signals in their firing behavior and by antidromic activation following stimulation of the oculomotor nucleus. The goal of these studies is to characterize the signal processing for each of the VS neural populations with respect to the different functional roles of the VCR. The signal processing will be quantified and related to behavioral goals of the reflex to determine functional roles of each pathway. The results of these studies are not only significant to our understanding of the sensory-motor control of head movements but are also globally applicable to the control of all vestibular postural reflexes because their mechanisms likely utilize similar neural processing strategies.

描述(申请人提供)：姿势反射是由各种感官输入引起和控制的。前庭-脊髓(VS)通路将前庭感觉信号传递到脊髓的广泛区域，在那里它们与运动核团相互作用，产生反射性运动。前庭-结肠反射(VCR)是姿势反射的一个重要子集，在身体受到干扰时通过重新调整头部的方向来避免潜在的颈部损伤。参与产生VCR的颈部运动核团接受来自两个不同的VS神经元群体的输入，这两个群体在解剖学上的区别是没有或存在到动眼神经核的侧支投射。我们假设，这两个不同的VS群体在控制反射性头部运动和反射性凝视移动(结合眼睛和头部)方面都很重要。为了验证这一假说，我们将记录清醒松鼠猴在反射性、自主性和被动性头部运动过程中前庭核团VS神经元的放电行为。这只猴子将坐在前庭的转盘上，只能在水平半规管的平面上产生不同的自主和反射性头部运动组合。在自愿和反射性头部运动期间的反应将相对于头部不被允许相对于身体移动的旋转期间的反应进行量化。次级VS神经元将从前庭神经顺行识别，并逆行识别为投射到脊髓。投射到动眼神经核的VS神经元将通过其放电行为中眼动相关信号的存在以及刺激动眼神经核后的逆行激活来识别。这些研究的目的是根据VCR的不同功能来表征每个VS神经种群的信号处理。信号处理将被量化，并与反射的行为目标相关，以确定每条通路的功能角色。这些研究的结果不仅对我们理解头部运动的感觉-运动控制具有重要意义，而且也适用于所有前庭姿势反射的控制，因为它们的机制可能使用类似的神经处理策略。