Neural Control of Head Stabilization and Tracking

描述（由申请人提供）：头颈部运动系统在运动控制层级中占据独特的位置。根据行为背景，它在三个相当不同的运动功能中起着重要的作用：头部稳定，扫视和平滑跟踪头部运动和自愿的，非视觉引导的头部运动。我们将集中在两个强大的下行投射到颈部运动神经元：前庭脊髓和网状脊髓神经元。为了开始填补我们对这些磁头控制电路的性质的知识的主要空白，我们提出了针对以下三个目标的实验。 1. 描述和比较猴子在三维空间中执行前庭稳定头部运动、缓慢跟踪头部运动和快速扫视头部运动时颈部肌肉活动的模式。我们将寻找证据，证明在执行一个动作时使用了多种肌肉模式。 2. 探索单一的逆行性前庭脊髓和网状脊髓神经元在产生目标1中研究的头部运动中的作用。神经元将根据它们携带的眼睛和头部运动相关信号的类型进行分类。我们将研究这些神经元如何实现大脑的能力，以抵消前庭头部运动信号，产生自头部运动。我们还将寻找多个中央控制器驱动自愿头部运动的证据。 3. 将神经解剖示踪剂注射到颈脊髓、脑干网状结构或投射到前庭核和网状结构的大脑皮质区域，以可视化灵长类动物颈部运动控制所涉及的通路。 头部运动控制受损是许多神经系统疾病的衰弱症状，包括中风、脑瘫、帕金森病和前庭神经病。通过增加我们对中枢神经系统如何控制头部的理解，该项目应该为更好地治疗这些疾病开辟道路。

DESCRIPTION (provided by applicant): The head-neck motor system occupies a unique place in the motor control hierarchy. Depending upon behavioral context, it plays an important role in three quite distinct motor functions: head stabilization, saccadic and smooth tracking head movements and voluntary, non-visually guided head movements. We will focus on two strong descending projections to neck motoneurons: vestibulospinal and reticulospinal neurons. To begin filling major gaps in our knowledge about properties of these head control circuits, we propose experiments directed at the following three aims. 1. Characterize and compare patterns of neck muscle activity that monkeys use to execute vestibular stabilizing head movements, slow tracking head movements and rapid saccadic head movements in three dimensions. We will look for evidence that multiple muscle patterns are used in executing a movement. 2. Explore the role of single antidromically identified vestibulospinal and reticulospinal neurons in generating the head movements studied in Aim 1. Neurons will be classified according to the types of eye- and head-movement related signals they carry. We will examine how these neurons implement the brain's ability to cancel out vestibular head movement signals that arise from self-generated head movements. We will also look for evidence that multiple central controllers drive voluntary head movements. 3. Inject neuroanatomical tracers into the cervical spinal cord, brainstem reticular formation or regions of cerebral cortex projecting to vestibular nuclei and reticular formation to visualize pathways involved in neck motor control in primates. Impaired control of head movement is a debilitating symptom of many neurological disorders including stroke, cerebral palsy, Parkinson's disease and vestibular neuropathy. By increasing our understanding of how the CNS controls the head, this project should open the way to better treatment of these disorders.