NEUROBIOLOGY OF A SIMPLE OCULOMOTOR SYSTEM

脊椎动物基本运动的神经机制 活动可以有效地研究模型系统从其他 提供有限数量神经元的优势 细胞内技术和现代结构 分析. 其中一项活动，通常被称为眼科 反应，包括复杂的行为模式介导的 视觉和前庭系统：凝视、物体扫描和 固定和稳定的视网膜图像补偿 头部和身体的复杂空间位移。 人类的视力异常可以表明 中枢神经损伤和疾病。 更好地了解 复杂的多感觉眼神经系统的细胞组织 路径可以为研究提供有益的线索和建议 在生理上不太容易接近的脊椎动物上。 双翅目丽蝇属提供了这样一个模型 erythrocephala，它具有广泛的复杂的 眼部行为 在两种性别的全景运动elevant 补偿性的头部和身体运动。 物体是视觉空间 引起固定和定向行为。 在卡利弗拉有一个 眼睛的深刻性别二型性：在男性中， 受体，高视力区，和独特的性别特异性 视觉中枢的神经元 只有雄性才能维持 快速移动的小目标的锁定、跟踪和拦截 对象 这与两性在以下方面的共同行为不同： 其中全景流场是通过元素运动计算的- 探测器并中继到巨大的顶盖神经元。 最后， 机械感觉信息，来自战略性放置 平衡触觉的器官与视觉相结合 在离散的大脑中心的信息来源1） 至控制头部的胸部运动中枢的下行通路 和身体肌肉组织和2）中间神经元供应小脑样 中脑的高级中枢 这项研究将采用细胞内记录和染色， 以及复杂的光学和电子显微镜策略， 解剖已识别神经细胞的细胞组织， 运动神经元和肌肉组织的受体。 的 研究将集中在以下几个方面：1）视网膜组织 和视觉中间神经元的多模态反应特征; 2） 细胞内记录和突触关系的下行 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，关节病学，和 性能. 这项研究旨在拓宽我们的理解 视觉机械感觉控制的神经机制 眼球运动 一个完整的描述电机控制在这个 模型将有助于理解 复杂眼神经行为的电路和 在视觉追踪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.