Mechanisms of sensory transduction and sensory information coding

感觉转导和感觉信息编码机制

• 批准号: RGPIN-2016-03712
• 负责人: French, Andrew
• 金额: $ 2.4万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=651166
• 关键词: Mechanisms; sensory; transduction; information; coding

Detection of external and internal physical and chemical signals are essential processes for all living things. Our research is aimed at discovering fundamental mechanisms of three important sensory modalities, mechanosensation, vision and olfaction. Understanding how these senses work would have wide implications in fields such as medicine, agriculture and robotics. We use a combination of experimental approaches that include electrical recordings, molecular biology, optical imaging and bioinformatics to discover how primary sensory nerve cells detect and process sensory signals. We are also interested in how sensory transduction mechanisms are adapted to different environments and lifestyles, if they are modulated by neurochemicals, and what kinds of information about the detected signals are transmitted to the brain.***Mechanotransduction provides senses such as touch, hearing, and balance, and is also crucial for the control of movement and functions of many internal organs. We use an invertebrate model, the spider VS-3 slit-sense organ that allows unique electrophysiological and optical access to sensory neurons during mechanical stimulation. This model was previously limited by lack of genetic and molecular data, but we have recently created transcriptome libraries of spider peripheral and central nervous systems, developed software for targeted gene assembly, and assembled genes that code all major ion channel types, including all putative mechanotransduction channel families. These new data provide the basis for our proposed experiments to identify the molecular mechanisms of mechanotransduction.***Our vision work concentrates on basic mechanisms of light detection by photoreceptors. Current models of insect phototransduction are mainly based on one species, fruit flies, but different insects have evolved to respond appropriately to their environments and lifestyles, so we want to learn how vision has adapted to these differences. There is also a missing functional link in insect photoreceptors between the detection of photons into chemical signals, and the electrical changes in cell membranes that transmit information to the next stages. We recently developed methods to silence individual genes in insect eyes and will use this technique to unravel the molecular mechanisms involved.***We are also investigating early steps in insect olfaction, an important component of their behaviour and a target for pest control and prevention of insect borne disease. We are interested in the time dependence of olfaction because it is clearly important in processes such as mate detection via pheromones, and host selection from carbon dioxide pulsation. We have invented new ways of measuring olfactory time dependence, and are using this approach to learn more about the earliest steps in odor detection, and which components of the olfaction mechanisms control overall time dependence.*****

检测外部和内部的物理和化学信号是所有生物的基本过程。我们的研究旨在发现三个重要的感觉形式，机械感觉，视觉和嗅觉的基本机制。了解这些感官是如何工作的将在医学、农业和机器人等领域产生广泛的影响。我们使用实验方法的组合，包括电记录，分子生物学，光学成像和生物信息学，以发现初级感觉神经细胞如何检测和处理感觉信号。我们还对感觉传导机制如何适应不同的环境和生活方式感兴趣，如果它们受到神经化学物质的调节，以及关于检测到的信号的什么样的信息被传递到大脑。机械传导提供触觉、听觉和平衡等感觉，对于许多内脏器官的运动和功能的控制也至关重要。我们使用一个无脊椎动物模型，蜘蛛VS-3狭缝感觉器官，允许独特的电生理和光学访问感觉神经元在机械刺激。该模型以前受到缺乏遗传和分子数据的限制，但我们最近创建了蜘蛛外周和中枢神经系统的转录组文库，开发了靶向基因组装软件，并组装了编码所有主要离子通道类型的基因，包括所有推定的机械转导通道家族。这些新数据为我们提出的实验提供了基础，以确定机械转导的分子机制。我们的视觉工作集中在光感受器对光探测的基本机制上。目前的昆虫光传导模型主要基于一个物种，果蝇，但不同的昆虫已经进化到对它们的环境和生活方式做出适当的反应，因此我们想了解视觉如何适应这些差异。在昆虫光感受器中，将光子检测为化学信号与将信息传递到下一阶段的细胞膜中的电变化之间也存在缺失的功能联系。我们最近开发了沉默昆虫眼睛中单个基因的方法，并将使用这种技术来解开所涉及的分子机制。我们还在研究昆虫嗅觉的早期阶段，这是昆虫行为的重要组成部分，也是害虫控制和预防虫媒疾病的目标。我们对嗅觉的时间依赖性很感兴趣，因为它在通过信息素进行配偶检测和通过二氧化碳脉动进行宿主选择等过程中显然很重要。我们发明了测量嗅觉时间依赖性的新方法，并正在使用这种方法来更多地了解气味检测的最早步骤，以及嗅觉机制的哪些组成部分控制总体时间依赖性。*