Parabrachial nuclei
[2] The subparabrachialnucleus and lateral crescent send efferents to the nucleus of the solitary tract, ventrolateral medulla, and spinal cord, where they target many respiratory and autonomic cell groups.For example, a population of neurons in the external lateral parabrachial subnucleus that contain the neurotransmitter calcitonin gene-related peptide (CGRP) appears to be critical for relaying information about hypoxia (low blood oxygen) and/or hypercapnia (high blood CO2) to forebrain sites to “wake up the brain” (arouse) when breathing is inadequate to meet physiological demands during sleep.[13] A study in 2017, has shown this information to be relayed through the lateral parabrachial nucleus rather than the thalamus, which drives thermoregulatory behaviour.[17] The parabrachial nucleus relays satiety and pain-related signals to higher brain regions; when inhibited, this can produce "liking" responses to certain pleasurable stimuli, such as sweet taste.[18] The lateral parabrachial nucleus integrates sensory signals, primarily, but not exclusively, from low-threshold mechanoreceptors to initiate the wet dog shake behavior by which mammals remove water and irritants from their back and neck fur.