SUMMARY
Noradrenergic neurons of the locus coeruleus (LC-NE) are known to play an important role in arousal, emotion, memory and cognition. In the present study, we use fiber photometry combined with chemogenetic and optogenetic approaches to demonstrate a previously unrecognized role for LC-NE neurons in the modulation of feeding. We show that endogenous activity of LC-NE neurons is enhanced while approaching food and suppressed during feeding. These changes in LC activity during feeding behavior are attenuated as mice approach satiety, demonstrating that nutritional state modulates LC responses to food. Direct activation of LC-NE neurons results in the suppression of feeding. Further, activation of an LC projection to the lateral hypothalamus also suppresses feeding. Together, these findings demonstrate a direct causal role for LC-NE activity in the modulation of feeding.
