Morphological and Physiological Analysis of the Motor Units of the Major Flight Muscles in the Pigeon (Columba livia) and the Starling (Sturnus vulgaris)

我的学生和我从事脊椎动物神经肌肉和肌肉骨骼系统的研究，重点是功能和进化。我们使用包括高速摄影和肌电图术在内的各种技术来检查肢体运动学、肌肉设计和脊髓组织。这项研究的重点是对鸟类肩部的功能分析。该项目旨在提供鸟类翅膀运动的神经控制最终建模和测试所需的基本形态和生理数据。有证据表明，肌肉是根据运动神经元的特定突触属性排序的，这些属性与大小有关。然而，理论上的考虑导致了对鸟类内部运动单位排序的另一种假设。为了帮助阐明这一重要问题，我们正在研究两个飞行风格不同的物种中分离的飞行肌肉运动单位的生理特征以及它们的外周和中枢解剖组织。这项研究旨在解决有关主要脊椎动物群体中神经肌肉组织进化的基本问题。对鸟类的研究也将为评估目前对早中生代陆生始龙肩部翅膀进化起源的解释(主要基于对鸟类化石始祖鸟的研究)提供有用的数据。除非我们完全了解现存物种飞行的肌肉骨骼和神经肌肉基础，否则我们对四足动物飞行进化这一基本问题的理解将受到阻碍。

My students and I are engaged in studies of the vertebrate neuromuscular and musculoskeletal systems with an emphasis on function and evolution. We examine limb kinematics, muscle design and spinal cord organization using a variety of techniques including high-speed photography and electromyography. The particular focus of this study is functional analysis of the Avian shoulder. The project is designed to yield basic morphological and physiological data requisite for the eventual modeling and testing of the neural control of wing movements in birds. Evidence exists from studies of muscle is ordered according to specific synaptic properties of the motoneuron which relate to size. Theoretical considerations, however, have resulted in alternative hypotheses for the ordering of motor unit within birds. To help clarify this important issue, we are studying the physiological profiles of isolated flight muscle motor units as well as their peripheral and central anatomical organization in two species with contrasting flight styles. This study is designed to address fundamental questions concerning the evolution of neuromuscular organization across the major vertebrate groups. Studies of birds will also provide data useful for evaluating current interpretations (based primarily on studies of the fossil bird Archaeopteryx) of the evolutionary origin of wings from the shoulder of early Mesozoic terrestrial archosaurs. Until we fully understand the musculoskeletal and neuromuscular basis of flight in a extant species, our understanding of the fundamental issue of the evolution of flight among tetrapods will be hampered.