BRC-BIO: Trade-offs in locomotor performance: comparing hoppers and jumpers in variable environments

生物体在环境或栖息地中航行的方式可能会受到个体的生理和环境物理特性的影响。更具体地说，有机体与之相互作用的底物可能会在运动运动中构成各种挑战，从而影响性能。运动中的适应需要有机体的神经系统、解剖学和肌肉生理学之间的动态相互作用，这些共同驱动着全身的运动。然而，一种动物使用的生理策略可能不太适合不同的栖息地或底物类型。这项研究旨在了解特殊的运动方式，更具体地说，跳跃和跳跃如何限制有机体对环境瞬时变化的反应。青蛙和蟾蜍提供了一个独特的模型来理解运动策略的变化。这个项目将研究全身运动和神经系统对肌肉招募的控制，以响应底物硬度的变化。此外，该项目还将研究肌腱组织的力学和组织，以更好地了解肌腱僵硬在特殊运动形式中的作用。肌肉和肌腱生理学上的这种独特的适应性可以告知不同栖息地环境变化对运动的影响，以及处理环境干扰的工程系统中的设计参数。这项研究的更广泛影响将增加对STEM历史上代表性不足的本科生的研究机会和指导，并使以教育研讨会为基础的培训和资源的开发能够增加整个母校获得STEM研究机会的机会。纵观历史，新的运动模式的出现对动物在新的栖息地导航的能力起到了至关重要的作用。例如，微生境之间的行为转变可能会导致动物运动策略的更微妙的变化。在某些情况下，运动系统可能足够灵活，以适应环境的物理属性的变化。这项拟议的工作旨在了解专门的运动方式如何对运动控制策略和肌肉肌腱特性产生独特的限制。为了解决这个问题，第一个目标将量化和比较甘蔗蛙的长距离耐力跳跃和古巴树蛙的快速有力跳跃之间的种间运动学差异，以响应环境对基质硬度的扰动。第二个目的是在活体内测量后肢肌肉长度和运动模式对基质硬度的响应，以表征长距离耐力漏斗所使用的运动控制机制。第三个目标是利用透射电子显微镜和连续块面扫描电子显微镜技术对肌腱的超微结构进行定量。最后，肌腱材料的性能将使用体外肌腱组织应力和应变测试来量化，以确定不同运动和功率输出模式的不同物种之间组织硬度的作用。这项拟议的研究将促进人们对不同运动模式的专业化如何在不同级别的生理组织中提供强大的好处或限制的理解。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The way an organism navigates an environment or habitat can be influenced by an individual’s physiology and the physical properties of its environment. More specifically, the substrate an organism interacts with can pose various challenges during locomotor movements that can impact performance. Adaptations in movement require a dynamic interplay between an organisms’ nervous system, anatomy, and muscle physiology, which together drive whole-body movements. However, the physiological strategies that one animal uses may not be ideally suited for a different habitat or substrate type. This research aims to understand how specialized ways of movement, more specifically, how hopping and jumping may constrain how an organism responds to instantaneous changes in the environment. Frogs and toads provide a unique model to understand variation in movement strategies. This project will investigate whole-body movement and nervous system control of muscle recruitment in response to changes in substrate stiffness. In addition, the project will investigate the mechanics and organization of tendon tissue to better understand the role of tendon stiffness in specialized forms of movement. Such unique adaptations in muscle and tendon physiology can inform the impacts of changing environments across habitats on locomotion, as well as design parameters in engineered systems dealing with environmental disturbance. The broader impacts of this research will increase research opportunities and mentorship of undergraduate students historically underrepresented in STEM, as well as enable the development of educational workshop-based trainings and resources to increase access to STEM research opportunities across the home institution. Throughout history the emergence of new modes of locomotion has played a crucial role in an animal’s ability to navigate new habitats. For example, behavioral transitions between microhabitats may result in more subtle shifts in an animal’s locomotor strategy. In some cases, the locomotor system may be flexible enough to accommodate changes in the physical properties of the environment. The proposed work aims to understand how specialized ways of movement have uniquely constrained motor control strategies and muscle-tendon properties. To address this, the first aim will quantify and compare interspecific kinematic variation between the long distance, endurance hopping of Cane toads, and the fast, powerful jumps of Cuban tree frogs, in response to environmental perturbations in substrate stiffness. The second aim measures in vivo hindlimb muscle length and motor patterns in response to substrate stiffness to characterize the motor control mechanisms used by long distance endurance hoppers. The third aim seeks to characterize tendon ultrastructure by quantifying collagen fibril organization using techniques in transmission electron microscopy and serial block-face scanning electron microscopy. Lastly, tendon material properties will be quantified using in vitro tendon tissue stress and strain tests to determine the role of tissue stiffness across species specialized for differing modes of locomotion and power output. The proposed research will advance understanding of how specialization in different locomotor modes can provide robust benefits or limitations at various levels of physiological organization.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.