Vestibular Regulation of Respiratory Muscle Activity

各种实验方法已经证实，前庭系统有助于 胸腹呼吸泵肌肉活动的调节以及 调节上呼吸道在运动和体位变化时的阻力。然而，这些影响 是复杂的，以至于前庭系统在调节空气在前庭和前庭中的运动的生理作用 目前还不清楚是从肺里出来的。当前提案的具体目标1将通过审查确定这一作用 双侧迷路切除对空气交换压力、容量和流量的影响 在吸气和呼气过程中，身体相对于重力的方向发生了变化。先前的实验已经 还表明，将前庭信号传递给呼吸运动神经元的一些神经元位于 内侧延髓网状结构，但这些细胞不足以产生前庭呼吸 回应。我们的解剖学研究和其他人的生理研究表明， 运动前呼吸神经元位于脊髓内。《特定目标2》将检验这一假说 中间神经元是神经元回路中的元素，它介导前庭系统对运动的影响 空气进出肺部。呼吸肌的模式化收缩是另外一个原因 产生呕吐；前庭信号在与运动相关的呕吐期间触发这种运动活动 生病了。然而，引起呕吐的神经回路尚未建立，尽管最近 有证据表明，内侧延髓网状结构中的细胞是其中的重要组成部分。 路径。特定目标3将检验内侧延髓网状结构神经元相互协调的假设 呕吐引起呕吐的呼吸肌的模式放电，包括与呕吐有关的呕吐 晕车。总之，这些实验应该确定迷宫信号的特殊作用 用于调节呼吸肌的活动，以补偿重力对这些肌肉的影响 肌肉、呼吸道和肺部。此外，前驱运动的位置和生理特性 在姿势改变时，介导迷路对呼吸运动神经元放电影响的神经元 和复仇，将会被确定。

A variety of experimental approaches have established that the vestibular system contributes to making adjustments in the activity of thoracic and abdominal respiratory pump muscles as well as muscles that regulate the resistance of the upper airway during movement and changes in posture. However, these effects are complex, such that the physiological role of the vestibular system in regulating the movement of air in and out of the lungs is not yet clear. Specific Aim 1 of the current proposal will determine this role by examining the consequences of a bilateral labyrinthectomy on the pressure, volume, and flow rate of air exchanged during inspiration and expiration as body orientation with respect to gravity is altered. Prior experiments have also shown that some of the neurons that relay vestibular signals to respiratory motoneurons are located in the medial medullary reticular formation, but that these cells are insufficient to produce vestibulo-respiratory responses. Our anatomical studies and physiological studies by others have revealed that additional premotor respiratory neurons are located in the spinal cord. Specific Aim 2 will test the hypothesis that spinal interneurons are elements in the neuronal circuit that mediates vestibular system influences on the movement of air in and out of the lungs. Patterned contractions of respiratory muscles are additionally responsible for producing vomiting; vestibular signals trigger this motor activity during emesis associated with motion sickness. However, the neural circuit that elicits vomiting has not yet been established, although recent evidence suggests that cells in the medial medullary reticular formation are important components in this pathway. Specific Aim 3 will test the hypothesis that medial medullary reticular formation neurons coordinate the patterned discharges of respiratory muscles that underlie vomiting, including emesis associated with motion sickness. Together, these experiments should establish the particular role that labyrinthine signals serve in adjusting the activity of respiratory muscles to compensate for the effects of gravity on these muscles, the airways, and the lungs. In addition, the location and physiological characteristics of premotor neurons that mediate labyrinthine influences on respiratory motoneuron firing, both during postural alterations and emesis, will be ascertained.