Dopamine and the Social Brain

In a recent article for Seed, Jonah Lehrer writes about new research from the neuroscientist Read Montague linking dopamine to complex social phenomena.

There is so much great stuff in the article that I find it difficult to quote just one piece. I’ve decided on this anecdote that I happen to find slightly amusing:

The importance of dopamine was discovered by accident. In 1954 James Olds and Peter Milner, two neuroscientists at McGill University, decided to implant an electrode deep into the center of a rat’s brain. The precise placement of the electrode was largely happenstance: At the time the geography of the mind remained a mystery. But Olds and Milner got lucky. They inserted the needle right next to the nucleus accumbens (NAcc), a part of the brain dense with dopamine neurons and involved with the processing of pleasurable rewards, like food and sex.

Olds and Milner quickly discovered that too much pleasure can be fatal. After they ran a small current into the wire, so that the NAcc was continually excited, the scientists noticed that the rodents lost interest in everything else. They stopped eating and drinking. All courtship behavior ceased. The rats would just cower in the corner of their cage, transfixed by their bliss. Within days all of the animals had perished. They had died of thirst.

It took several decades of painstaking research, but neuroscientists eventually discovered that the rats were suffering from an excess of dopamine.

This review on Mind Hacks is a good complement to the article.

Update: The above quoted anecdote reminded me of another article detailing some extreme cases of erotic self-stimulation using brain implants. This one, from a lady who had a deep brain stimulation (DBS) device implanted to help with chronic pain:

At its most frequent, the patient self-stimulated throughout the day, neglecting personal hygiene and family commitments. A chronic ulceration developed at the tip of the finger used to adjust the amplitude dial and she frequently tampered with the device in an effort to increase the stimulation amplitude. […] During the past two years, compulsive use has become associated with frequent attacks of anxiety, depersonalization, periods of psychogenic polydipsia and virtually complete inactivity.