NEURAL BASIS OF FORM PERCEPTION IN A MODEL VISUAL SYSTEM

这个建议调查的神经基础的方向和形式 非脊椎动物模式系统，双翅目Phaenicia 绢毛的。这项研究将确定与以下方面有关的视觉参数： 低水平的形式视觉使用行为测试。然后，它将使用 这些参数作为测试滤波器特性的刺激， 在具有神经解剖学特征的神经元中识别出神经元， 类似于哺乳动物视觉皮层的特征。了解 视觉感知机制，单细胞研究 必须在详细的背景下进行 形态学分析使得单个神经元的结构 对特定视觉刺激的反应可能与整体 系统的神经解剖学背景。双翅目昆虫的复眼 光学瓣为这种研究提供了理想的基底。的 视叶的视网膜定位组织神经柱的连续性是 在功能上类似于哺乳动物视觉系统中的组织 区域，但包含数量级更少的神经元。在 特别是，计划的研究将集中在小叶， 由该视觉系统的小细胞成分提供的神经纤维 并在其中包含结构上 类似于哺乳动物皮层的锥体和星状神经元。的 该模型系统的相对简单性有助于 识别单个计算单元并允许详细 电路分析这种简单系统的另一个优点是， 它反映了视觉系统进化上保守的原则 跨越系统发育界限的设计。提议的遗嘱 调查：.双翅目昆虫区分 包含方向和纹理的视觉图案和形状 信息. .神经元和回路的细胞特性 区分方向和纹理的小叶。.的 类神经元和星状神经元的解剖结构 在双翅目昆虫的小叶中

This proposal investigates the neural basis of orientation and form perception by a non-vertebrate model system, the dipteran Phaenicia sericata. The research will identify visual parameters pertinent to low-level form vision using behavioral tests. It will then employ these parameters as stimuli for testing the filter properties of identified neurons in a neuropil having neuroanatomical characteristics analogous to mammalian visual cortex. To understand mechanisms of visual perception, investigations at the single cell level must be performed against a background of detailed morphological analysis such that the structure of single neurons responding to specific visual stimuli can be related to the overall neuroanatomical context of the system. The dipteran compound eye and optic lobes offer an ideal substrate for such an investigation. The optic lobes' succession of retinotopically organized neuropils is functionally analogous to organization amongst mammalian visual regions, but contains orders of magnitude fewer neurons. In particular, the planned research will focus on the lobula, a neuropil supplied by the parvicellular element of this visual system and containing within it nerve cells that are structurally analogous to pyramidal and stellate neurons of mammalian cortex. The relative simplicity of this model system facilitates the identification of single computational units and allows detailed circuit analysis A further advantage of this simple system is that it reflects evolutionarily conserved principles of visual system design that cut across phylogenetic boundaries. The proposed will investigate: . the ability of a dipteran species to discriminate visual patterns and shapes containing orientation and texture information. . the cellular properties of neurons and circuits in the lobula that discriminate orientations and textures. . the anatomical organization of pyramidal-like and stellate-like neurons in the dipteran lobula.