Dopamine
What exactly is "Dopamine" in the brain system?
Scientists identify connection between dopamine and behavior related to pain and fear. Scientists have for the first time found direct causal links between the neurotransmitter dopamine and avoidance -- behavior related to pain and fear. Researchers have long known that dopamine plays a key role in driving behavior related to pleasurable goals, such as food, sex and social interaction. In general, increasing dopamine boosts the drive toward these stimuli. But dopamine's role in allowing organisms to avoid negative events has remained mysterious. Source 1k.
Dopamine's yin-yang personality: It's an upper and a downer. Dopamine has a reputation as the key player in the brain's reward circuits, making us seek out pleasurable experiences, but growing evidence points to a multipronged role for the neurotransmitter. In particular, dopamine may also reinforce avoidance of painful experiences. Researchers have now mapped dopamine neurons in the brain with fiber photometry and discovered two parallel dopamine circuits driving attractive and aversive reinforcement learning and motivation. Source 6i.