Locus coeruleus anchors a trisynaptic circuit controlling fear-induced suppression of feeding.

The circuit mechanisms underlying fear-induced suppression of feeding are poorly understood. To help fill this gap, mice were fear conditioned, and the resulting changes in synaptic connectivity among the locus coeruleus (LC), the parabrachial nucleus (PBN), and the central nucleus of amygdala (CeA)-all of which are implicated in fear and feeding-were studied. LC neurons co-released noradrenaline and glutamate to excite PBN neurons and suppress feeding.