NEUROBIOLOGY OF A SIMPLE OCULOMOTOR SYSTEM

脊椎动物基本运动的神经机制 活动可以在其他模型系统中进行有用的研究 具有神经元数量有限的优势的门 可利用细胞内技术和现代结构 分析。 其中一种活动通常称为动眼神经 反应，包括由以下因素介导的复杂行为模式 视觉和前庭系统：凝视、物体扫描和 固视和视网膜图像补偿的稳定性 用于头部和身体的复杂空间位移。 人类动眼神经异常可能预示着 中枢神经创伤和疾病。 更深入地了解 复杂的多感觉动眼神经的细胞组织 途径可以为研究提供有用的线索和建议 在生理上难以接近的脊椎动物对应物上。 双翅目 Calliphora 提供了一种这样的模型 erythrocephala，具有广泛的复杂 动眼行为。 在两性中，全景运动都会引起 头部和身体的代偿性运动。 物体是视觉空间 引起固定和定向行为。 在 Calliphora 有一个 眼睛的深刻性别二态性：男性有更多 受体，一个高视力区域，并且具有独特的性别特异性 视觉中枢的神经元。 只有男性才能维持 固定、跟踪和拦截快速移动的小型物体 对象。 这与男女共有的行为不同 哪些全景流场是通过基本运动计算的 探测器并转发给巨大的顶盖神经元。 最终， 机械感觉信息，源自战略性放置 平衡器官 触觉与视觉相结合 离散大脑中心的信息源自 1) 下行通路至胸部运动中枢控制头部 和身体肌肉组织和 2) 供应小脑样的中间神经元 中脑的高级中心。 这项研究将采用细胞内记录和染色， 以及复杂的光和电子显微镜策略 解剖已识别神经细胞的细胞组织，从 运动神经元和肌肉组织的受体。 的 研究将集中在以下方面：1）视网膜专题组织 视觉中间神经元的多模态反应特征； 2） 细胞内记录和下行突触关系 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。 这项研究旨在拓宽我们的理解 参与视觉机械感觉控制的神经机制 眼球运动。 电机控制的完整描述在此 模型将为理解迈出重要一步 复杂动眼行为的电路及其作用 视觉追踪和拦截中独特识别的神经元。

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.