Vestibulo-cerebellar contribution to spatial adaptation

前庭小脑对空间适应的贡献

• 批准号: 7014554
• 负责人: NEAL H BARMACK
• 金额: $ 32.53万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-26 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7014554
• 关键词: brain electrical activity; cerebellar Purkinje cell; cerebellum; electrostimulus; head movements; laboratory rabbit; microelectrodes; nystagmus; olivary body; orientation; semicircular duct; vestibular apparatus; vestibular pathway; vestibuloocular reflex

DESCRIPTION (provided by applicant): We propose three areas of investigation to understand how the circuitry of the vestibulocerebellum uses vestibular information to modify the simple spike (SS) output of Purkinje cells and how this output contributes to behavioral adaptation to altered vestibular orientation: 1) Circuitry transmitting vestibular information to inferior olive. The parasolitary nucleus (Psol) conveys vestibular signals to the beta-nucleus and dorsomedial cell column (dmcc), two subnuclei of the inferior olive. Unilateral lesions of Psol reduce, but do not eliminate vestibularly-modulated climbing fiber responses (CFRs) in the contralateral uvula-nodulus, implying an alternative presynaptic vestibular pathway to the inferior olive. The Y-group may be the origin of this alternative pathway. We will combine retrograde and orthograde tracers with recordings from single Y-group neurons to determine the types of vestibular and optokinetic signals carried by them. 2) Conjunctive CFR-SS vestibular plasticity in the nodulus, understanding interactions between climbing and parallel fibers on Purkinje cells is critical to understanding the cerebellum. Interactions occur with short- or long-term consequences. We will electrically stimulate parallel and climbing fibers in vivo so that their interactions can be interpreted in terms of known vestibular circuitry. A climbing fiber volley from a known semicircular canal zone in the beta-nucleus, will be interacted with a parallel fiber volley from a single vertical semicircular canal. These interactions should reveal how climbing fiber topography is reflected in Purkinje cell output. 3) Behavioral evaluation of the role of the uvula-nodulus in the dynamic control of vestibule-ocular reflex orientation in space. Rotation of rabbits about a longitudinal axis modulates the velocity and orientation of a previously induced optokinetic afternystagmus (OKAN II). The significance of decreases in nystagmus velocity and the possible contribution of the nodulus to modification of eye velocity are poorly understood. We suggest that head tilt induces a reduction in nystagmus velocity to reduce the gain of all eye reflexes that conflict perceived vertical orientation or a previously "remembered" orientation. We will measure changes in slow phase velocity when the orientation of the rabbit's head causes nystagmus to be executed at different angles within the orbit before and after bilateral destruction of the uvula-nodulus.

描述（由申请人提供）：我们提出了三个研究领域，以了解前庭小脑的电路如何使用前庭信息来修改浦肯野细胞的简单尖峰（SS）输出，以及这种输出如何有助于改变前庭方向的行为适应：1）将前庭信息传递到下橄榄的电路。旁孤束核（Psol）将前庭信号传递到下橄榄核的两个亚核β核和背内侧细胞柱（dmcc）。单侧病变Psol减少，但不消除前庭调制攀爬纤维反应（CFRs）在对侧悬雍垂结节，这意味着另一种突触前前庭通路下橄榄。Y-基团可能是这种替代途径的起源。我们将联合收割机将逆行和顺行示踪剂与单个Y组神经元的记录结合起来，以确定它们携带的前庭和视动信号的类型。2)结合CFR-SS前庭可塑性的结节，了解之间的相互作用浦肯野细胞上的攀爬和平行纤维是至关重要的了解小脑。相互作用会产生短期或长期后果。我们将在活体内电刺激平行纤维和攀爬纤维，以便根据已知的前庭回路来解释它们的相互作用。来自β-核中已知半规管区的攀爬纤维排，将与来自单个垂直半规管的平行纤维排相互作用。这些相互作用应揭示如何攀登纤维地形反映在浦肯野细胞输出。3)悬雍垂-结节在空间前庭-眼反射定向动态控制中作用的行为学评价。兔子绕纵轴旋转调节先前诱导的视动性后眼球震颤（OKAN II）的速度和方向。眼球震颤速度降低的意义和结节对眼速度改变的可能贡献知之甚少。我们认为，头部倾斜引起眼球震颤速度减少，以减少所有的眼睛反射，冲突感知垂直方向或以前的“记忆”方向的增益。我们将测量当兔子头部的方向导致眼球震颤时慢相速度的变化，在双侧悬雍垂结节破坏之前和之后，在眼眶内以不同的角度执行。