Integrated pathways that control stress and energy homeostasis

Key advances Neuropeptide Y expressed in central amygdala (CeA) neurons is critical to drive feeding under chronic stress conditions, which lead to the accelerated development of obesity when combined with calorically dense food5. Palatable food increases the activity of CeA prepro-nociceptin neurons, which leads to an increase in reward properties via changes in functions of the striata terminalis, the parabrachial nucleus and the nucleus of the solitary tract7. Pro-opiomelanocortin neurons in the arcuate nucleus are specifically activated by restraint stress, which is associated with an increase in feeding and reduction in depression-like behaviour that is mediated by an alteration in ventral tegmental area9. Aversive emotional states are integrated with other homeostatic bodily functions in the posterior visceral insular cortex, which then subsequently alters feeding via the nucleus accumbens and anxiety behaviour via amygdala connections10. Feeding is regulated by defined neuronal pathways and circulating factors that ensure homeostatic balance is maintained. However, many emotion-affective pathways are also involved in communicating positive and negative valence on feeding behaviour. In 2019, several seminal discoveries were made that illuminate the complex interaction between homeostatic and hedonic feeding control mechanisms.