The innate attraction to sweet mediates appetitive and consummatory responses. Here, we dissected the circuit driving responses to sweet and showed that amygdala neurons tuned to sweet connect to the bed nucleus of the stria-terminalis (BNST) to promote sweet-evoked consumption. Next, we demonstrate that the BNST functions as a central hub, transforming appetitive signals into consumption and linking sensory inputs to the internal state, not only for sweet but also for other stimuli such as salt or food, to flexibly regulate consummatory behaviors. Using single-cell functional imaging, we show that ensemble activity in the BNST encodes stimulus identity and the animal's internal state. Finally, we demonstrate that manipulating BNST activity can bidirectionally transform consummatory responses. Together, these findings illustrate how the internal state modulates sensory responses, characterize a general brain dial for consumption, and provide fresh insights into sites of action of GLP1R agonists and a strategy to help promote weight gain in pathological states.
Canovas et al. (Mon,) studied this question.