Dopamine helps us learn what may be worth pursuing. Serotonin participates in regulation and adaptation. Acetylcholine helps direct attention and translate neural intention into muscular action. Noradrenaline prepares the brain to notice and respond. None of them acts alone. And these four are not the entire chemical orchestra. Glutamate, GABA, histamine, endorphins, endocannabinoids, neuropeptides, hormones and immune signals also contribute to human thought, emotion and b

A family history of Alzheimer's feels like a sentence already written. The evidence tells a more complicated, more hopeful story — one where genetics hands you a blueprint, and how you live still determines a great deal of what actually gets built.