NEURAL MECHANISMS IN PROCESSING VISUAL INFORMATION

处理视觉信息的神经机制

• 批准号: 3257675
• 负责人: ANN E STUART
• 金额: $ 19.99万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-08-01 至 1991-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3257675
• 关键词: Cirripedia; calcium channel; cell membrane; electrical potential; electron microscopy; eye accommodation; gamma aminobutyrate; interneurons; membrane channels; membrane structure; motor neurons; neural information processing; neural transmission; neuroanatomy; neurotransmitters; photostimulus; saltwater environment; synapses; visual pathways; visual photoreceptor; visual photosensitivity

The visual system of the giant barnacle has proved useful for studying photoreceptor synapses as well as signal detection, amplification, and adaptation, in a simple visual pathway. A total of ten huge photoreceptors, divided amongst three eyes, project to a ganglion where visual information is processed by a small number of neurons. The similarity of the physiology of the receptors and postsynaptic cells to that of cells of the vertebrate retina makes this system attractive for studying membrane and synaptic properties and circuitry underlying visual processing. We propose experiments to understand the mechanisms of synaptic transmission from these photoreceptors, where it is possible to impale the presynaptic terminal regions, control its voltage, and simultaneously impale the postsynaptic cell. We particularly hope to understand the adaptation shown to occur at this synapse. Using techniques of voltage clamp and optical recording we will ask: 1. What are the properties of the Ca channels in the presynaptic membrane? How does the presynaptic intracellular Ca concentration change with the transient and prolonged stimuli? What is the voltage profile in the terminal arbor during prolonged depolarizations? 2. What is the transmitter released by the photoreceptors? What is the size of the quantal unit released? We also propose to record from and voltage clamp second- and third-order cells to explore certain aspects of processing of visual signals. 3. How are off-responses generated in the second-order cell, particularly over a wide range of background light intensities? 4. How does signal compare to noise at various backgrounds in the receptors and second-order cells, and how does convergence improve signal detection? 5. What specific information is encoded in each of the known third-order cells and what are the mechanisms of their off-responses?

巨型藤壶的视觉系统已被证明可用于研究 光感受器的突触以及信号检测，扩增和 适应，以简单的视觉途径。 总共十个巨大 感光体，分为三只眼睛，投射到神经节 视觉信息由少数神经元处理。 这 受体和突触后细胞生理学与 脊椎动物视网膜细胞的细胞使该系统对 研究膜和突触性能以及视觉视觉的电路 加工。 我们建议实验了解突触的机制 从这些光感受器传播，可能会凸出 突触前终端区域，控制其电压，同时控制其电压 凸出突触后细胞。 我们特别希望了解 适应在此突触处发生。 使用电压技术 夹具和光学记录，我们会问： 1。突触前膜中CA通道的特性是什么？ 突触前细胞内Ca浓度如何随着 短暂的和长时间的刺激？ 什么是电压轮廓 长时间去极化期间的末端植物？ 2。光感受器释放的发射器是什么？ 什么是 释放量化单位的大小？ 我们还建议从二阶和三阶记录和电压夹 细胞探索视觉信号处理的某些方面。 3。如何在二阶单元格中产生非响应。特别是 在广泛的背景光强度上？ 4。信号与受体中各种背景的噪声相比如何 和二阶细胞，收敛如何改善信号检测？ 5。在每个已知的三阶中编码哪些特定信息 细胞，其异常的机制是什么？