Interoception— the ability to sense the body’s internal state—allows us to consciously and unconsciously maintain homeostasis. Sensory neurons of the nodose and petrosal ganglia (NPG) serve as a major pathway for transmitting vital interoceptive signals about our respiratory, digestive, and circulatory systems to the brain. However, despite the wide array of physiological cues signaled by this neural pathway, very little is known about the molecular diversity of the neurons which monitor our internal state. Here we leverage transcriptomic insight and the power of mouse genetics to start to interrogate the molecular logic of interoception as it relates to breathing. We find: – NPG neurons are molecularly diverse – P2RY1(+) neurons contribute to regulating the hypoxic ventilatory response – Hypoxia, sensed by the carotid body, is not communicated by P2RY1(+) neurons – NPG neurons integrate carotid body transduction of multiple stimuli (O2, CO2, pH) – P2RY1(+) neurons innervate NEBs in the lungs How the brain is informed of a body’s hypoxic or hypercapnic state is relevant for understanding sleep apnea and sleep fragmentation. Elucidation of the neural circuitry of breathing regulation, particularly at the blood-gas primary reception level and the point of first neural encoding, could reveal exciting therapeutic targets for sleep medicine.