Extreme Performance at Low Temperature: Ballistic Tongue Projection in Salamanders and Chameleons

低温下的极限性能：蝾螈和变色龙的弹道舌头投射

• 批准号: 0842626
• 负责人: Stephen Deban
• 金额: $ 23.77万
• 依托单位: University of South Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0842626&HistoricalAwards=false
• 关键词: Extreme; Performance; Low; Temperature; Ballistic

Environmental temperature has profound effects on the physiological processes of animals whose body temperature is determined by their surroundings, such as reptiles and amphibians. The ability of such animals to be active at low temperatures is limited by the slowing of physiological processes such as the speed of muscle contraction. The explosive movements of ballistic tongue projection in salamanders and chameleons are unusual in maintaining extremely high performance across a broad range of temperatures. This study will examine the physiological and biomechanical processes that confer this high performance and temperature insensitivity. Tongue projection is powered by rapid elastic recoil of collagen tendon-like structures (in a "bow and arrow" mechanism) which frees the dynamics of the movement from the dynamics of muscle contraction. This mechanism may endow this system and other musculoskeletal systems with an expanded thermal breadth of high performance, because the elastic recoil of collagen has a much lower temperature sensitivity than muscle contraction speed and power. This study will use high-speed digital imaging and recordings of muscle activation patterns during tongue projection, and measurements of the speed and power of muscle contractions, each at a range of temperatures. The combined data will enable a robust test of this elastic recoil model, and data from two independently evolved systems -salamanders and chameleons - will permit a test of the model's generality and predictive power. The results will further our understanding of the complex interplay of environment, biomechanics and physiology, which cannot be confidently predicted from first principles. Results will also provide testable predictions about the thermal responses of diverse biological systems with elastic components. Tongue projection is a highly engaging and effective vehicle for communicating discoveries in physiology and biomechanics, and is ideal for recruiting and training students in all aspects of scientific research. The results may also have practical applications in the design of prosthetic devices and sports equipment that improve performance and the functional range of muscles.

环境温度对动物的生理过程有着深刻的影响，动物的体温由其周围环境决定，如爬行动物和两栖动物。这种动物在低温下活动的能力受到生理过程（如肌肉收缩速度）减慢的限制。在火蜥蜴和变色龙中，弹道式舌头投射的爆炸性运动在很宽的温度范围内保持极高的性能是不寻常的。本研究将研究赋予这种高性能和温度不敏感性的生理和生物力学过程。舌头伸出是由胶原肌腱样结构的快速弹性回缩提供动力的（在“弓箭”机制中），这将运动的动力学从肌肉收缩的动力学中解放出来。这种机制可以赋予该系统和其他肌肉骨骼系统以高性能的扩展的热宽度，因为胶原蛋白的弹性反冲具有比肌肉收缩速度和功率低得多的温度敏感性。这项研究将使用高速数字成像和记录舌头投射过程中的肌肉激活模式，并测量肌肉收缩的速度和力量，每种都在一定的温度范围内。综合数据将能够对这种弹性反冲模型进行强大的测试，来自两个独立进化系统-蝾螈和变色龙-的数据将允许测试模型的通用性和预测能力。这些结果将进一步加深我们对环境、生物力学和生理学之间复杂相互作用的理解，而这些相互作用是无法从第一原理中自信地预测的。结果还将提供可测试的预测不同的生物系统的弹性组件的热响应。舌头投影是一种非常吸引人和有效的工具，用于交流生理学和生物力学的发现，并且非常适合招募和培训科学研究各个方面的学生。这些结果也可能在假肢装置和运动器材的设计中有实际应用，这些装置和运动器材可以提高肌肉的性能和功能范围。