Which group of neurons is responsible for generating the rhythm of breathing?

The dorsal respiratory group (DRG) is primarily responsible for generating the rhythm of breathing. This group of neurons is located in the medulla oblongata of the brainstem and plays a critical role in the control of inspiration. The DRG receives sensory information regarding the state of the respiratory system and is involved in the rhythmic activation of the respiratory muscles, particularly the diaphragm and intercostal muscles, to facilitate inhalation.

While the ventral respiratory group (VRG) also contributes to the overall regulation of breathing patterns, especially during forced respiration and active expiration, the primary rhythmic drive for normal, quiet respiration largely originates from the DRG. The pneumotaxic center, located in the pons, modulates the transition between inhalation and exhalation but does not directly generate the respiratory rhythm. The corticobulbar tract is primarily involved in voluntary control of muscles and is not directly related to the automatic rhythmic generation of breathing as managed by the brainstem's respiratory centers.