Nicotine triggers the release of norepinephrine from the locus coeruleus, acting as a wake-up signal that elevates energy levels.

“nicotine accomplishes those increases in alertness and arousal and energy within the brain is by triggering the release of no epinephrine from a little cluster of neurons in the back of the brain called locus coeruleus, tiny cluster of neurons that offers up, or I should say has, because they're always there from birth has these little wires, these axons that extend many, many places in the brain, not every place, but virtually every place and can sprinkler the brain with norepinephrine, essentially serve as a wake up signal, elevating levels of energy.”