Context-specific Spatial Adaptation of the VOR

VOR 的特定环境空间适应

• 批准号: 7904959
• 负责人: SERGEI YAKUSHIN
• 金额: $ 34.68万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7904959
• 关键词: Affect; Animals; Behavior; Behavioral; Binding; Cells; Central cord canal structure; Characteristics; Code; Data; Dependence; Development; Dimensions; Equilibrium; Eye; Eye Movements; Force of Gravity; Frequencies; Goals; Head; Helping Behavior; Hour; Investigation; Learning; Left; Lesion; Measures; Medial; Modeling; Modification; Monkeys; Motor Neurons; Muscle; Neural Network Simulation; Neurons; Oculomotor nucleus; Output; Pathway interactions; Positioning Attribute; Process; Property; Relative (related person); Research; Saccades; Side; Space Perception; Spatial Distribution; Speed; Structure; Sum; System; Testing; Vestibular nucleus structure; Weight; Work; Yaws; base; cranial vestibular nucleus structure; experience; insight; models and simulation; neuromechanism; novel strategies; oculomotor; otoconia; research study; response; simulation; vector; vestibulo-ocular reflex; visual-vestibular

DESCRIPTION (provided by applicant): Gravity is an important context for adapting the angular vestibulo-ocular reflex (aVOR) by visual-vestibular mismatch. Maximal gain changes occur in the position of adaptation and decrease, as the head is oriented away from this position. The spectral components of the gravity-dependent adaptation are also tuned to the frequency of adaptation. A study is proposed to determine the cellular basis for the gravity and frequency dependent aspects of this adaptation in the vestibular nuclei of the alert monkey. The frequency characteristics of gravity dependent adaptation will first be studied to determine how adaptation at one frequency affects adaptation over a wide range of frequencies and head orientations. This will lay the groundwork for studying adaptive changes in canal-ocular transduction and reorientation of otolith polarization vectors in central vestibular neurons. Such studies will include: 1) Characterizing the cellular changes associated with gravity-dependent adaptation in the otolith polarization vectors of otolith-canal convergent neurons in the vestibular nuclei. 2) Investigating how adaptive changes in the otolith reorientation and canal-ocular transduction of canal-otolith convergent neurons at a particular frequency are related to the spatio-temporal convergence (STC) characteristics of the unit. Preliminary investigations show that when gravity-dependent adaptation is induced at a specific frequency, the canal-otolith convergent neurons developed STC characteristics that also tuned to the frequency of adaptation. 3) Determine how FTN and PVP neurons code the gravity-dependent adaptation. 4) Tie these findings to a neuronal net model, which will form the underlying basis for the study. It is postulated that gravity- dependent adaptation is a spatio-temporal process, which is encoded in the STC characteristics of canal- otolith convergent units. It is further proposed that vestibular-only (VO) neurons in the vestibular nuclei transmit this information through the flocculus to floccular target neurons (FTN) and directly to position- vestibular-pause (PVP) cells that code gravity dependent adaptation.The proposed research will determine the neural mechanism for the dependence of adaptation of the vestibulo-ocular reflex on gravity. This could provide a new approach to explaining difficulties in balance and spatial orientation commonly encountered after lesions of the vestibular system.

描述（由申请人提供）：重力是通过视觉-前庭失配来适应角前庭眼反射（aVOR）的重要背景。当头部远离该位置时，最大增益变化发生在适应位置并减小。重力相关适应的频谱分量也被调整到适应频率。一项研究旨在确定警觉猴前庭核适应重力和频率相关方面的细胞基础。首先将研究依赖于重力的适应的频率特性，以确定某一频率的适应如何影响大范围频率和头部方向的适应。这将为研究中央前庭神经元耳石偏振矢量的耳管-眼转导的适应性变化和重新定向奠定基础。此类研究将包括： 1) 表征与前庭核中耳石管会聚神经元的耳石极化矢量的重力依赖性适应相关的细胞变化。 2）研究特定频率下耳石重新定向和耳管-耳石会聚神经元的耳管-眼转导的适应性变化如何与单元的时空会聚（STC）特征相关。初步研究表明，当以特定频率诱导重力依赖性适应时，耳管-耳石会聚神经元会产生 STC 特征，这些特征也适应适应频率。 3) 确定 FTN 和 PVP 神经元如何编码重力依赖性适应。 4）将这些发现与神经网络模型联系起来，这将构成研究的基础。假设重力依赖性适应是一个时空过程，它被编码在管耳石收敛单元的 STC 特征中。进一步提出，前庭核中的前庭（VO）神经元通过絮状细胞将这些信息传递给絮状目标神经元（FTN），并直接传递给编码重力依赖性适应的位置前庭暂停（PVP）细胞。将确定前庭眼反射适应重力的神经机制。这可以提供一种新方法来解释前庭系统损伤后常见的平衡和空间定向困难。