Vestibulo-spinal influences on reflex performance

前庭脊髓对反射性能的影响

• 批准号: 6725128
• 负责人: Greg Thomas Gdowski
• 金额: $ 37.94万
• 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/6725128
• 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（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递到脊髓的广泛区域，在那里它们与运动核相互作用产生反射运动。前庭-结肠反射（VCR）是姿势反射的一个重要子集，它通过在身体扰动时重新定位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种不同的VS神经元群的输入，这两种VS神经元在解剖学上是通过有无向动眼核的侧支投射来区分的。我们假设这两种不同的VS种群在控制反射性头部运动和反射性目光转移（眼睛和头部结合）方面都很重要。为了验证这一假设，我们将记录位于前庭核的VS神经元在清醒的松鼠猴的反射性、自发性和被动头部运动中的放电行为。猴子将被安置在一个前庭转盘上，并被允许在水平半规管的平面上产生不同的自发性和反射性头部运动组合。自主性和反身性头部运动时的反应将与头部不允许相对于身体运动时的旋转时的反应进行量化。次级VS神经元将从前庭神经正反方向识别，并被识别为投射到脊髓。投射到动眼核的VS神经元将通过在其放电行为中存在眼动相关信号以及在刺激动眼核后的反向激活来识别。这些研究的目的是表征每一个VS神经群体的信号处理相对于VCR的不同功能角色。信号处理将被量化，并与反射的行为目标相关，以确定每个通路的功能角色。这些研究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。