Your brain contains a mind-blowing number of nerves—about 1,200 cubic centimeters of nerves, which is only a bit larger than a quart of milk (946 cubic centimeters). In an instant, your miraculous brain can be moving your arms and legs, thinking about what you’ll have for dinner, remembering a conversation you had yesterday or a memory from elementary school, figuring out a problem, talking to a friend, and feeling love, hope, and joy. Doing those jobs for you are four primary chemicals: dopamine, serotonin, norepinephrine, and acetylcholine. Learn which nutrients increase these important neurohormones to promote healthy focus, memory, energy, mood, and recall.