Zhang J W, Walker J F, Guardiola J, Yu J
Pulmonary Div., Department of Medicine. University of Louisville, KY 40292, USA.
J Appl Physiol (1985). 2006 Sep;101(3):986-92. doi: 10.1152/japplphysiol.00161.2006. Epub 2006 May 4.
Mouse model research is proliferating because of its readiness for genetic manipulation. Little is known about pulmonary vagal afferents in mice, however. The purpose of this study was to determine whether their pulmonary afferents are similar to those in large animals. Single-unit activity was recorded in the cervical vagus nerve of anesthetized, open-chest, and mechanically ventilated mice. We evaluated airway sensory activity in 153 single units; 141 were mechanosensitive, with 134 inflation receptors and 7 deflation receptors. The remaining 12 receptors were chemosensitive and mechanically insensitive, showing low basal firing frequency and behaving like C-fiber or high-threshold Adelta-receptors. In separate studies, phrenic activity was recorded as an index of respiratory drive to assess pulmonary reflexes. Lung inflation produced a typical Hering-Breuer reflex, and intravenous injection of phenylbiguanide produced the typical chemoreflex resulting in apnea, bradycardia, and hypotension. These reflexes were blocked by bilateral vagotomy. We conclude that mice possess a similar set of airway sensors and pulmonary reflexes as typically found in larger animals.
由于小鼠易于进行基因操作，小鼠模型研究正在迅速增加。然而，人们对小鼠的肺迷走传入神经知之甚少。本研究的目的是确定它们的肺传入神经是否与大型动物的相似。在麻醉、开胸和机械通气的小鼠的颈迷走神经中记录单单位活动。我们评估了153个单单位的气道感觉活动；其中141个是机械敏感的，包括134个肺扩张感受器和7个肺萎陷感受器。其余12个感受器是化学敏感但机械不敏感的，表现出低基础放电频率，类似于C纤维或高阈值Aδ受体。在另外的研究中，记录膈神经活动作为呼吸驱动的指标以评估肺反射。肺扩张产生典型的黑林-布雷尔反射，静脉注射苯乙双胍产生典型的化学反射，导致呼吸暂停、心动过缓和低血压。这些反射被双侧迷走神经切断所阻断。我们得出结论，小鼠拥有与大型动物中通常发现的相似的一组气道感受器和肺反射。
