NEUROBIOLOGY OF SIMPLE OCULOMOTOR SYSTEM

脊椎动物基本运动的神经机制 可以在模型系统中有效地研究来自其他 提供有限数量神经元的优势的门 可使用细胞内技术和现代结构 分析。其中一种活动，通称为动眼神经 反应，由复杂的行为模式组成，由 视觉和前庭系统：凝视、物体扫描和 定影，以及视网膜图像的稳定化补偿 用于头部和身体的复杂空间位移。 人类的眼球运动异常可提示 中枢神经创伤和疾病。更好地理解 复杂多感觉性动眼神经的细胞组织 路径可以为研究提供有用的线索和建议 在生理上较难接近的脊椎动物上。 一个这样的模型是由双翅目Calliphora提供的 红头藻，它有广泛的复杂的 动眼神经行为。在两性中，全景运动引发了 代偿性的头部和身体动作。物体是视觉空间 引发凝视和定向行为。在Calliphora有一种 眼睛的深刻性二形性：男性有更多 感受器，视觉敏锐度高的区域，具有独特的性别特异性 视觉中心的神经元。只有雄性才能维持 快速运动小目标的定位、跟踪和拦截 物体。这与男性和女性在 其中的全景流场是由元素运动计算的- 并传递给巨大的顶盖神经元。最终， 机械感官信息，源自战略位置 平衡触觉的器官与视觉是一体的 起源于离散大脑中心的信息1) 通向胸部运动中枢控制头部的下行通路 和身体肌肉组织以及2)供应小脑样物质的中间神经元 中脑的高级中枢。 这项研究将使用细胞内记录和染色， 以及复杂的光学和电子显微镜策略来 解剖已识别的神经细胞的细胞组织，来自 运动神经元和肌肉系统的受体。这个 主要研究内容如下：1)视网膜组织 和视觉中间神经元的多模式反应特征；2) 降支的细胞内记录和突触关系 运动神经元；3)神经支配、生理学和动力学 效应肌；4)骨骼附着、关节学和 行为。这项研究建议拓宽我们的理解 涉及视觉-机械感觉控制的神经机制 眼球运动。在这篇文章中对电机控制的完整描述 模型将有助于理解 复杂眼动行为的回路及其作用 在视觉追逐和拦截中唯一识别的神经元。

Neural mechanisms underlying fundamental vertebrate motor activities can be usefully studies in model systems from other phyla which offer the advantage of a limited number of neurons accessible to intracellular techniques and modern structural analysis. One such activity, generically known as the oculomotor response, comprises complex patterns of behaviour mediated by the visual and vestibular systems: gaze, object scanning and fixation, and the stabilization of the retinal image compensating for complex spatial displacements of the head and body. Oculomotor abnormalities in humans can indicate the onset of central nervous trauma and disease. A greater understanding of the cellular organization of a complex multisensory oculomotor pathway could provide useful leads and suggestions for research on the physiologically less accessible vertebrate counterpart. One such model is provided by the dipteran Calliphora erythrocephala, which has a wide range of sophisticated oculomotor behaviours. In both sexes panoramic motion elicits compensatory head and body movements. Objects is visual space elicit fixation and orientation behaviour. In Calliphora there is a profound sexual dimorphism of the eye: in males there are more receptors, a zone of high visual acuity, and unique sex-specific neurons in the visual centers. Only males are able to sustain fixation, tracking and interception of small rapidly moving objects. This is distinct from behaviour shared by both sexes in which panoramic flow fields are computed by elemental motion- detectors and relayed to giant tectal neurons. Ultimately, mechanosensory information, derived from strategically placed organs for balance tactile perception is integrated with visual information in discrete brain centers from which originate 1) descending pathways to thoracic motor centers controlling head and body musculature and 2) interneurons supplying cerebellarlike higher centers in the midbrain. This research will employ intracellular recordings and stainings, and sophisticated light and electron microscopical strategies to dissect the cellular organization of identified nerve cells, from the receptors to the motor neurons and musculature. The research will focus on the following: 1) retinotopic organization and multimodal response characteristics of visual interneurons; 2) intracellular recordings and synaptic relationships of descending motor neurons; 3) innervation, physiology, and dynamics of effector muscles; 4) skeletal attachment, arthrology, and behaviour. This research proposes to broaden our understanding of neural mechanisms involved in visuo-mechanosensory control of eye movements. A complete description of motor control in this model will contribute a major step towards understanding circuitry for complex oculomotor behaviour and the role of uniquely identified neurons in visual pursuit and interception.