Dopamine is infamous as a pleasure-inducing brain chemical: It's the neurotransmitter released when you smoke a cigarette or snort cocaine. But a new study published today shows that dopamine is also key to keeping people terrified for long periods.
Specifically, dopamine is responsible for making you remember frightening experiences in the long term, rather than forgetting them right away.
Researchers studied the effect of dopamine on rats who had been terrified by having their paws electrically shocked. What the scientists discovered was that dopamine had no affect on the rats' memories if it was given shortly after the shock. But if the rats were given chemicals that reduced the amount of dopamine absorbed by their neurons about 12 hours later - roughly the time it takes for the brain to consolidate long-term memories - they forgot the painful experience quickly and walked right onto the foot-shocking device again. However, rats who received chemicals 12 hours later that enhanced the amount of dopamine absorbed remembered the foot-shocking device far longer than they might have otherwise. Their fear of foot shock remained quite vivid.
Let this be a lesson to all authoritarian regimes who want to rule with fear and drugs. Feed your population with dopamine promoters 12 hours after the public executions. Their terror and awe will last a lot longer, and you'll get a bigger bang for each buck you pay your death squads.