Thorén P, Shepherd J T, Donald D E
J Appl Physiol Respir Environ Exerc Physiol. 1977 Mar;42(3):461-5. doi: 10.1152/jappl.1977.42.3.461.
In anesthetized cats examination was made of the conditions under which the application of DC current to a mixed nerve permits determination of whether a reflex response is mediated by medullated or nonmedullated afferents. The following precautions should be observed. The nerve must be stripped of its sheath and bleeding avoided. The anode should be 6 mm distant from the cathode. The temperature of the mineral oil surrounding the nerve should be 30-32 degrees C to avoid activation of nonmedullated fibers during the block. The major limitation is a time- and frequency-dependent block of nonmedullated fibers which makes the technique suitable only for differentiating between medullated fibers and nonmedullated fibers with low frequency traffic. Observing these criteria, anodal block of the cervical vagus in sino-aortic denervated cats resulted in a mean rise in aortic pressure of 8 Torr; subsequent cold block caused a further mean rise of 30 Torr. Thus 80% of the total increase in aortic pressure could be ascribed to interruption of vagal C-fiber activity.
在麻醉猫身上，研究了向混合神经施加直流电时的条件，以确定反射反应是由有髓传入纤维还是无髓传入纤维介导的。应注意以下预防措施。必须去除神经的鞘膜并避免出血。阳极应距阴极6毫米。神经周围矿物油的温度应为30 - 32摄氏度，以避免在阻断过程中激活无髓纤维。主要限制是无髓纤维的时间和频率依赖性阻断，这使得该技术仅适用于区分低频活动的有髓纤维和无髓纤维。遵循这些标准，在去窦主动脉神经的猫中，颈迷走神经的阳极阻断导致主动脉压平均升高8托；随后的冷阻断导致进一步平均升高30托。因此，主动脉压总升高的80%可归因于迷走C纤维活动的中断。
