Various afferent inputs influencing the neuronal control of tracheal smooth muscle

本研究揭示了影响胸外气管活动的各种传入输入静脉注射氰酸刺激外周化学感受器引起气管平滑肌收缩椎动脉注射CO_2饱和生理盐水激活中枢化学感受器引起气管收缩3 .椎体内注射饱和生理盐水可引起气管扩张，提示脑干缺血引起气管扩张肺膨胀对肺拉伸受体的刺激引起气管张力的松弛。迷走神经切开术后肺部膨胀导致了一种矛盾的反应，即气管收缩上呼吸道刺激物受体的兴奋使气管平滑肌的活动增加电刺激股神经近端引起气管扩张。目前的研究还表明，通过电刺激猫的髓网状结构内的有限区域，可以产生打嗝样反应（对声门关闭的短暂有力的吸气努力）。有效部位定位于歧义核外侧区域。这一发现表明，在脑干下部存在一个协调打嗝反射的神经网络。

The present study revealed various afferent inputs that influenced the activity of the extrathoracic trachea.1 Excitation of the peripheral chemoreceptor by intravenous injection of cyanic acid produced a constriction of tracheal smooth muscle.2 Activation of the central chemoreceptor by intra-vertebral arterial injection of CO_2 saturated saline caused tracheal constriction.3 Intravertebral injection of N_2 saturated saline elicited a dilatation of the trache, indicating that ischemia of the brainstem causes tracheal dilation.4 Stimulation of the pulmonary stretch receptor by lung inflation evoked a relaxation of tracheal tone. The lung inflation after vagotomy resulted in a paradoxical response, i.e., a constriction of the trachea.5 Excitation of the irritant receptor of the upper airway produced the increased activity of the tracheal smooth muscle.6 Electrical stimulation of the proximal end of the femoral nerves elicited the tracheal dilatation.The present study also demonstrated that a hiccup-like response (a brief powerful inspiratory effort against glottic closure) were generated by electrical stimulation to a limited area within the medullary reticular formation of the cat. The effective sites were localized in the region lateral to the nucleus ambiguus. This finding indicates that there is a neuronal network coordinating the hiccup reflex within the lower brainstem.