Mechanosensitive Channels in C.elegans Sensory Perception

线虫感官知觉中的机械敏感通道

• 批准号: 6812501
• 负责人: LAURA BIANCHI
• 金额: $ 11.66万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6812501
• 关键词: Caenorhabditis elegans; avoidance behavior; behavior test; biological signal transduction; calcium flux; calcium indicator; electrophysiology; gene targeting; genetically modified animals; helminth genetics; membrane channels; neurogenetics; neurons; neurophysiology; osmotic pressure; perception; protein structure function; sensory signal detection; touch; water channel

DESCRIPTION (provided by applicant): In nature, mechanical signaling plays fundamental roles in processes as diverse as cell volume regulation and the senses of touch and hearing. Recent work in nematodes, flies and mammals has implicated DEG/ENaC and TRP ion channels in osmo- and touch- sensation. Still, little is understood of how these channels function in vivo and how their activities are coordinated to maximize perception. In this proposal I combine experimental approaches uniquely applicable in C. elegans to characterize specific DEG/ENaC and TRP channels that act in well-characterized neurons to mediate mechanosensory perception. Aim I. I have identified a novel TRP-like stretch-sensitive ion channel in body touch neurons that is independent of the MEC-4 DEG/ENaC ion channel that senses gentle touch. Using in vivo calcium imaging, we have also found that touch receptors respond to harsher touch via a mechanism independent of MEC-4. My hypothesis is that the novel stretch-sensitive ion channel mediates calcium transients elicited by harsh touch and is required for normal responses to harsh touch, I will further characterize the stretch-sensitive channel, identify its gene and generate a knockout to test for its role in harsh touch behavioral responses. Aim II. In independent experiments I found that two novel DEG/ENaCs are expressed in the polymodal sensory neurons ASH (known to also require TRP channels OSM-9 and OCR-2 for function). DEG/ENaC deg-1 is co-expressed in these neurons. I have null mutants for all three DEG/ENaCs and I found that at least one of them (others are untested) shows defects in ASH-mediated nose touch response and osmolarity avoidance behavior. I will combine genetic, electrophysiological, behavioral, and imaging approaches to fully characterize the roles of DEG/ENaCs in ASH neuronal function. At completion of this work, I will be well positioned to address whether TRPs and DEG/ENaCs are functionally redundant or whether they "sense" distinct stimuli

描述（由申请人提供）：在本质上，机械信号传导在与细胞体积调节和触摸和听力的过程中的过程中扮演着基本角色。在线虫，苍蝇和哺乳动物中的最新工作已将DEG/ENAC和TRP离子通道牵涉到OSMO和触摸感中。尽管如此，这些渠道在体内的功能以及如何协调以最大程度地提高感知的方式了解了几乎没有什么理解的。在此提案中，我将独特适用于秀丽隐杆线虫的实验方法结合在一起，以表征在特征良好的神经元中作用的特定DEG/ENAC和TRP通道，以介导机械感知感知。 AIM I.我已经确定了身体触摸神经元中新型TRP的拉伸敏感离子通道，该通道独立于MEC-4度/ENAC离子通道，可以感觉到温和的触摸。使用体内钙成像，我们还发现触摸受体通过独立于MEC-4的机制对更严格的触摸做出反应。我的假设是，新型的拉伸敏感的离子通道介导了严格的触摸引起的钙瞬变，并且是对严格触摸的正常响应所必需的，我将进一步表征伸展敏感的通道，识别其基因并产生敲除以测试其在恶劣触摸行为反应中的作用。目标II。在独立的实验中，我发现在多载体感觉神经元灰分中表达了两个新的DEG/ENAC（已知还需要TRP通道OSM-9和OCR-2才能进行功能）。 DEG/ENAC DEG-1在这些神经元中共表达。我的所有三个度/ENAC都有空突变体，我发现其中至少一个（未经测试的）显示了灰介导的鼻子触摸响应和渗透压避免行为的缺陷。我将结合遗传，电生理，行为和成像方法，以充分表征DEG/ENAC在灰神经元功能中的作用。完成这项工作后，我将很适合解决TRP和DEG/ENAC在功能上是多余的，还是它们“感知”不同的刺激