Effects of various lesions on crossed and uncrossed descending inspiratory pathways in the cervical spinal cord of the cat

Abstract

✓ Various cervical spinal cord lesions interrupting portions of the descending respiratory pathways were made in 12 cats. Results suggest: 1) that the descending inspiratory pathways lie in the ventrolateral portion of the high cervical spinal cord; 2) that a decussation of these pathways exists between the low medullary and high cervical level; 3) that fibers descend via both crossed and uncrossed pathways along the length of the cervical cord to innervate phrenic nuclei bilaterally; 4) that activity in the crossed pathway running along the length of the cervical cord is related to the level of PaCO2.