Vestibulo-spinal influences on reflex performance

前庭脊髓对反射性能的影响

基本信息

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
项目类别：
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

项目摘要

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（由申请人提供）：姿势反射是由各种感觉输入引起和控制的。前庭脊髓 (VS) 通路将感觉前庭信号传送到脊髓的广泛区域，在那里它们与运动核相互作用以产生反射性运动。前庭结肠反射 (VCR) 是姿势反射的重要子集，可在身体扰动期间通过重新定向头部来避免潜在的颈部损伤。参与产生 VCR 的颈部运动核接收来自两个不同 VS 神经元群体的输入，这两个神经元在解剖学上通过是否存在到动眼神经核的附带投射来区分。我们假设这两个不同的 VS 群体对于控制反射性头部运动和反射性凝视转移（眼睛和头部的组合）很重要。为了验证这一假设，我们将记录清醒松鼠猴在反射性、自愿性和被动性头部运动期间位于前庭核的 VS 神经元的放电行为。猴子将坐在前庭转盘上，并被允许仅在水平半规管平面内产生不同的自愿和反射性头部运动组合。当不允许头部相对于身体移动时，将根据旋转期间的响应来量化自愿和反射性头部运动期间的响应。次级 VS 神经元将从前庭神经顺向识别，并从逆向识别为投射到脊髓。投射到动眼核的 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核后的逆向激活来识别。这些研究的目标是根据 VCR 的不同功能角色来表征每个 VS 神经群的信号处理。信号处理将被量化并与反射的行为目标相关联，以确定每个通路的功能作用。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，而且在全球范围内适用于所有前庭姿势反射的控制，因为它们的机制可能利用类似的神经处理策略。