Sensorimotor control of the oropharynx and esophagus

描述（由申请人提供）：鸣禽是为数不多的人类语言动物模型之一，可以通过实验研究与产生复杂的、习得的发声相关的基本生理和声学挑战。最近，在鸟类中发现了新的与歌唱相关的运动程序，这些程序可以调节声门上声道的大小，使其充当一个可变共振过滤器，跟踪发声器官产生的声音的基本频率，从而加强了语言产生和鸟鸣之间的相似之处。下面的研究重点是口咽-食道腔（OEC）的感觉运动控制，它主导着声道过滤器。长期目标是增加我们对神经系统如何控制复杂行为的理解。第一个具体目标是使用显微解剖，MRI和CT扫描对鸣禽头颈部进行详细的功能形态学分析。所获得的数据将与唱歌时声道运动的x线摄影相结合。由此产生的运动学模型将通过添加生物物理、生理和生化因素的体内和体外测量来确定相关声道肌肉的收缩性能。将这些数据包含在模型中，将有可能将运动学模型转换为与歌曲相关的声道运动的动态3D生物力学模型。第二个具体目标是调查感官反馈在OEC保持其共振频率调谐到歌曲基本频率的能力中的作用，这是由鸣管控制的。射线摄影将与通过震耳术、音高转移的声音输出或改变基频来操纵感觉反馈来确定感觉反馈在控制声道滤波器中的作用，使它们的共振与基频相匹配。体感反馈在调节声道过滤器中的可能作用也将被研究。第三个具体目标将使用神经解剖学和神经生理学技术来绘制脑神经的运动前通路，以确定听觉信息通过运动神经元进入上声道肌肉的神经通路，并寻找与控制发声器官的大脑歌曲控制核的可能神经连接。鸣禽提供了一个有价值的模型系统，用于研究与各种语言病理相关的一些控制机制，这些机制对公共卫生很重要。

DESCRIPTION (provided by applicant): Songbirds are one of the few animal models for human speech in which it is possible to experimentally investigate basic physiological and acoustic challenges associated with producing complex, learned vocalizations. Parallels between the production of speech and birdsong have recently been strengthened by the discovery in birds of new song-related motor programs that modulate the dimensions of the supra glottal vocal tract, causing it to act as a variable resonance filter that tracks the fundamental frequency of sound generated in the vocal organ. The following research focuses on sensorimotor control of the oropharyngeal-esophageal cavity (OEC), which dominates the vocal tract filter. A long-term goal is to increase our understanding of how the nervous system controls complex behaviors. The first specific aim is to perform a detailed functional morphological analysis of the songbird head and neck, using micro dissection, MRI and CT scan. The data obtained will be combined with that from cineradiography of vocal tract movements during song. The resulting kinematic model will be elaborated by the addition of in vivo and in vitro measures of biophysical, physiological and biochemical factors determining the contractile performance of the relevant vocal tract muscles. The inclusion of these data in the model will make it possible to convert the kinematic model into a dynamic 3D biomechanical model of song-related vocal tract movements. The second specific aim investigates the role of sensory feedback in the OEC's ability to keep its resonance frequency tuned to the song's fundamental frequency, which is controlled by the syrinx. Cineradiography will be combined with manipulation of sensory feedback by deafening, pitch shifting vocal output or altering the fundamental frequency to determine the role of sensory feedback in controlling vocal tract filters so their resonance matches the fundamental frequency. The possible role of somatosensory feedback in tuning the vocal tract filter will also be investigated. The third specific aim will use neuroanatomical and neurophysiological techniques to map the premotor pathways of the cranial nerves in order to identify the neural pathways by which auditory information accesses the motoneurons to muscles of the upper vocal tract and to look for possible neural connections to the brain's song control nuclei, which controls the vocal organ. Songbirds provide a valuable model system in which to investigate some of the control mechanisms relevant to various speech pathologies that are important to public health. PUBLIC HEALTH RELEVANCE: Disorders of speech are of substantial significance, yet animal models in which to study the physiological basis of learned vocal communication are surprisingly rare. The role of sensory feedback in motor coordination during speech production is poorly understood. The knowledge gained from this research will improve our understanding of the integration between the vocal organ and articulatory movements of the upper vocal tract and have implications for speech fluency disorders, including stuttering.