VTA
Ventral tegmental area: a small patch of the midbrain, at the top of the brainstem, that is one of the brain's main sources of dopamine. Its cells respond to rewards, to signs a reward is coming, and to new things.
The ventral tegmental area, VTA for short, sits deep in the brain at the top of the brainstem, next to its neighbour the substantia nigra. Many of its cells make dopamine and send it forward: to the striatum, which drives wanting, and to the front of the brain and the memory areas. Evidence: solid In monkeys, these dopamine cells fire most for rewards that are better than expected and, once learned, for the signs that a reward is coming. Evidence: solid
In brain scans, the VTA and its neighbour together were more active with things that were genuinely new than with familiar things that were only rare or unpleasant. Evidence: decent It also became more active when people newly and intensely in love looked at a photo of their partner. Evidence: decent Scans track blood flow, not dopamine itself, so they show the area at work, not the dopamine it releases. Evidence: decent
Why it matters
When a hack says something new "wakes up the dopamine cells", these are the cells. They're likely part of why new experiences feel worth chasing. Evidence: decent In animals they also help new things stick in memory; in people that's less direct. Evidence: decent