Researchers find 'switch' for brain's pleasure pathway

March 22, 2006

Amid reports that a drug used to treat Parkinson's disease has caused some patients to become addicted to gambling and sex, University of Pittsburgh researchers have published a study that sheds light on what may have gone wrong.

In the current issue of Proceedings of the National Academy of Sciences, Pitt professor of neuroscience, psychiatry, and psychology Anthony Grace and Pitt neuroscience research associate Daniel Lodge suggest a new mechanism for how the brain's reward system works.

The main actor in the reward system is a chemical called dopamine. When you smell, touch, hear, see, or taste a pleasurable stimulus, the dopamine neurons in your brain start firing in bursts. So-called "burst firing" is how the brain signals reward and modulates goal-directed behavior. But just how the stimulus you perceive causes neurons to switch into or out of this mode has been a mystery.

Using anesthetized rats, Lodge and Grace found that one area in the brain stem, known as the laterodorsal tegmental nucleus, is critical to normal dopamine function.

"We've found, for the first time, the brain area that acts as the gate, telling neurons either to go into this communication mode or to stop communicating," says Grace. "All the other parts of the brain that talk to the dopamine neurons can only do it when this area puts them into the communication mode."

As a result, disruption in that area may play a major role in dopamine-related brain function, both in normal behaviors and psychiatric disorders.

The brain area identified by the Pitt researchers is regulated by the "planning" part of the brain, the prefrontal cortex (PFC), thereby providing a powerful indirect means for the PFC to affect the activity of dopamine neurons. Such a link could explain how changes in the PFC, seen in disorders like schizophrenia and drug addiction, disrupt the signaling of dopamine neurons.

Source: University of Pittsburgh

Explore further: Manganese speeds up honey bees

Related Stories

Manganese speeds up honey bees

March 24, 2015

Asked to name one way people have changed the environment, many people would probably say "global warming." But that's really just the start of it.

Activation of brain region can change a monkey's choice

May 29, 2014

Artificially stimulating a brain region believed to play a key role in learning, reward and motivation induced monkeys to change which of two images they choose to look at. In experiments reported online in the journal Current ...

Octopus got your tongue?

January 7, 2014

It's an unusual coupling: A linguist and a marine biologist are working together to investigate the human tongue. In their study, the USC Dornsife researchers are using two species of octopus and tiny worms that helped win ...

Recommended for you

A cataclysmic event of a certain age

July 27, 2015

At the end of the Pleistocene period, approximately 12,800 years ago—give or take a few centuries—a cosmic impact triggered an abrupt cooling episode that earth scientists refer to as the Younger Dryas.

New blow for 'supersymmetry' physics theory

July 27, 2015

In a new blow for the futuristic "supersymmetry" theory of the universe's basic anatomy, experts reported fresh evidence Monday of subatomic activity consistent with the mainstream Standard Model of particle physics.

Dense star clusters shown to be binary black hole factories

July 29, 2015

The coalescence of two black holes—a very violent and exotic event—is one of the most sought-after observations of modern astronomy. But, as these mergers emit no light of any kind, finding such elusive events has been ...

Image: Hubble sees a dying star's final moments

July 31, 2015

A dying star's final moments are captured in this image from the NASA/ESA Hubble Space Telescope. The death throes of this star may only last mere moments on a cosmological timescale, but this star's demise is still quite ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.