Explain the difference between epinephrine and norepinephrine

Epinephrine and norepinephrine are both neuromodulators that play roles in regulating energy levels and the activation of the immune system. Catecholamines like epinephrine, also known as adrenaline, are responsible for increasing energy and heightening alertness by activating neural circuits in the brain. They can affect physiological responses as well, such as dilating the pupils and increasing eye alertness 1. On the other hand, norepinephrine is specifically mentioned in the context of nicotine's effects, where it, along with epinephrine, increases alertness, energy, and arousal by being part of the neurochemical pathways activated by nicotine 2.

In summary:

• Epinephrine (adrenaline): Increases energy, elevates alertness, and affects physiological responses like pupil size and eye alertness.
• Norepinephrine: Often released alongside epinephrine, it contributes to increased alertness, energy, and arousal, particularly noted in the response to nicotine.

In terms of their differences, the provided clips from Huberman Lab do not delve into a detailed contrast between the two substances. However, they both serve to regulate energy and cognitive attention, with their levels being important for physical and mental energy 3.