Effects of carotid body excision on recovery of respiratory function in C2 hemisected adult rats

Spontaneous recovery of respiratory-related activity in the paralyzed hemidiaphragm (indicated by left phrenic nerve activity) was detected in all H-CBE animals while H-CBI animals did not express spontaneous recovery of diaphragmatic activity. The magnitude of recovered activity when expressed as a function of contralateral phrenic nerve activity was 48.8 ± 3.8%. When expressed as a function of the homolateral phrenic nerve in noninjured animals, the magnitude amounted to 25.6 ± 2.8%. Although the mechanisms responsible for the apparent early onset of spontaneous recovery are unknown, it is likely that a reorganization of the respiratory circuitry in the CNS may be involved. The significance of the findings is that it may be feasible to modulate the onset of functional recovery following cervical spinal cord injury by specifically targeting peripheral chemoreceptors.