延脊吸气神经元与膈神经核在脊髓平面交叉联系的电生理研究

Electrophysiological Investigation on Decussate Communication of Bulbospinal Inspiratory Neurons with Phrenic Nucleus at Level of Spinal Cord

在麻醉、切断双侧颈迷走神经、制动、人工通气下，对猫、家兔和大鼠进行实验。在颈２、３之间半横贯切割脊髓后，双侧膈神经节律性放电活动均存在；继而在颈３～５之间正中矢状切割脊髓后，半横贯对侧的膈神经放电依然存在，而同侧的完全消失。半横贯脊髓后，双侧膈神经放电幅度均降低，以同侧为甚。这些结果提示：延脊吸气神经元与膈神经核在脊髓平面存在着交叉联系，即一侧膈神经核接受来自双侧脊髓下行的吸气性驱动，以同侧为主。

The experiments were carried out onanesthetized,vagotomized,immobilized and artificiallyventilated cats,rabbits and rats. The rhythmic respi-ratory activities on both sides of the phrenic nerves ex-isted after a hemisection between the 2nd and 3rd cer-vical cord,while the activities of the phrenic nerve ip-silateral to the hemisection disappeared following asubsequent mid-sagittal section from the 3rd to 5thcervical cord.The amplitude of the phrenic activitieson either side was lowered,more remarkably on the ipsilateral side, by the hemisection. These results in-dicate that there exists a decussate communication ofthe bulbospinal inspiratory neurons with the phrenicnucleus at the level of spinal cord.In other words,thephrenic nucleus receives inspiratory drives via descend-ing pathways on both sides of the cervical cord,mainlyon the ipsilateral side.