The locus coeruleus is bidirectionally coupled with behaviors, releasing epinephrine when in action and activating the brain when active.

“Locus coeruleus is a brain structure that is tightly coupled with behaviors in a bidirectional way. That is, when you are in action, you increase the amount of epinephrine released from locus coeruleus. You wake up the brain. And conversely, when locus coeruleus is active, the brain wakes up, so it's reciprocal. It goes both directions.”