In transection at pontomedullary junction, respiration is maintained with slight irregularity. It is due to

Lesions of DRG, VRG neurons do not abolish respiratory activity because they apparently project to the pre-BOTC pacemaker neurons. The pre-Botzinger complex (preBotC) is a cluster of interneurons in the ventral respiratory group of the medulla of the brainstem. This complex has been proven to be essential for the generation of the respiratory rhythm in mammals.The exact mechanism of the rhythm generation and transmission to motor nuclei remains controversial and the topic of much research Reference: Ganong's Review of Medical Physiology; 25th edition; Page no 656, 657