Researchers find 'switch' for brain's pleasure pathway

Mar 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: How were fossil tracks made by Early Triassic swimming reptiles so well preserved?

add to favorites email to friend print save as pdf

Related Stories

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 ...

Octopus got your tongue?

Jan 07, 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 ...

Recommended for you

Predicting human crowds with statistical physics

Feb 27, 2015

For the first time researchers have directly measured a general law of how pedestrians interact in a crowd. This law can be used to create realistic crowds in virtual reality games and to make public spaces safer.

Bribery 'hits 1.6 billion people a year'

Feb 27, 2015

A total of 1.6 billion people worldwide – nearly a quarter of the global population – are forced to pay bribes to gain access to everyday public services, according to a new book by academics at the Universities of Birmingham ...

Broken windows thesis springs a leak

Feb 27, 2015

The broken windows theory posits that minor misdemeanors, like littering or graffiti spraying, stimulate more serious anti-social behavior. LMU sociologists now argue that the idea is flawed and does not ...

User comments : 0

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.