Study identifies brain circuits involved in learning and decision making

July 9, 2013, National Institutes of Health
brain

(Medical Xpress)—Research from the National Institutes of Health has identified neural circuits in mice that are involved in the ability to learn and alter behaviors. The findings help to explain the brain processes that govern choice and the ability to adapt behavior based on the end results.

Researchers think this might provide insight into patterns of such as alcoholism and other addictions.

"Much remains to be understood about exactly how the brain strikes the balance between learning a that is consistently rewarded, versus retaining the flexibility to switch to a new, better response," said Kenneth R. Warren, Ph.D., acting director of the National Institute on Alcohol Abuse and Alcoholism. "These findings give new insight into the process and how it can go awry."

The study, published online in Nature Neuroscience, indicates that specific circuits in the forebrain play a critical role in choice and .

Like other addictions, alcoholism is a disease in which voluntary control of behavior progressively diminishes and unwanted actions eventually become compulsive. It is thought that the normal involved in completing everyday activities become redirected toward finding and abusing alcohol.

The research, conducted by investigators from NIAAA, with support from the National Institute of Mental Health and the University of Cambridge, England, used a variety of approaches to study choice.

Researchers used a simple choice task in which mice viewed images on a computer touchscreen and learned to touch a specific image with their nose to get a . Using various techniques to visualize and record , researchers found that as the mice learned to consistently make a choice, the brain's dorsal striatum was activated. The dorsal striatum is thought to play an important role in motivation, decision-making, and reward.

Conversely, when the mice later had to shift to a new choice to receive a reward, the dorsal striatum quieted while regions in the prefrontal cortex, an area involved in decision-making and complex cognitive processes, became active.

Building upon these findings, the authors next deleted or pharmacologically blocked a component of nerve cells which normally binds the neurochemical glutamate (specifically, the GluN2B subunit of the NMDA receptor) within two different areas of the brain, the striatum and the frontal cortex. Previous studies have shown that GluN2B plays a role in memory, spatial reference, and attention. Researchers found that making dorsal striatal GluN2B inactive markedly slowed learning, while shutting down GluN2B in the prefrontal cortex made the mice less able to relearn the touchscreen reward task after the reward image was changed.

"These data add to what we understand about the neural control of behavioral flexibility and striatal learning by identifying GluN2B as a critical molecular substrate to both processes," said the study's senior author, Andrew Holmes, Ph.D., Laboratory Chief and Principal Investigator of the NIAAA Laboratory of Behavioral and Genomic Neuroscience.

"This is particularly intriguing for future studies because NMDA receptors are a major target for alcohol and contribute to important features of alcoholism, such as withdrawal. These new findings suggest that GluN2B in corticostriatal circuits may also play a key role in driving the transition from controlled drinking to compulsive abuse that characterizes alcoholism."

Explore further: Researchers identify pathway that may protect against cocaine addiction

More information: GluN2B in corticostriatal circuits governs choice learning and choice shifting, DOI: 10.1038/nn.3457

Related Stories

Researchers identify pathway that may protect against cocaine addiction

April 16, 2013
(Medical Xpress)—A study by researchers at the National Institutes of Health gives insight into changes in the reward circuitry of the brain that may provide resistance against cocaine addiction. Scientists found that strengthening ...

Breaking habits before they start

June 27, 2013
Our daily routines can become so ingrained that we perform them automatically, such as taking the same route to work every day. Some behaviors, such as smoking or biting your fingernails, become so habitual that we can't ...

Brain patterns may help predict relapse risk for alcoholism

May 2, 2013
(Medical Xpress)—Distinct patterns of brain activity are linked to greater rates of relapse among alcohol dependent patients in early recovery, a study has found. The research, supported by the National Institutes of Health, ...

Scientists advance understanding of brain receptor; may help fight neurological disorders

May 28, 2013
For several years, the pharmaceutical industry has tried to develop drugs that target a specific neurotransmitter receptor in the brain, the NMDA receptor. This receptor is present on almost every neuron in the human brain ...

Behavioral test shows promise in predicting future problems with alcohol

August 27, 2012
(Medical Xpress)—By administering a simple behavioral test, Yale researchers were able to predict which mice would later exhibit alcoholism-related behaviors such as the inability to stop seeking alcohol and a tendency ...

Receptor limits the rewarding effects of food and cocaine

July 12, 2011
(Medical Xpress) -- Researchers have long known that dopamine, a brain chemical that plays important roles in the control of normal movement, and in pleasure, reward and motivation, also plays a central role in substance ...

Recommended for you

Research reveals atomic-level changes in ALS-linked protein

January 18, 2018
For the first time, researchers have described atom-by-atom changes in a family of proteins linked to amyotrophic lateral sclerosis (ALS), a group of brain disorders known as frontotemporal dementia and degenerative diseases ...

Fragile X finding shows normal neurons that interact poorly

January 18, 2018
Neurons in mice afflicted with the genetic defect that causes Fragile X syndrome (FXS) appear similar to those in healthy mice, but these neurons fail to interact normally, resulting in the long-known cognitive impairments, ...

How your brain remembers what you had for dinner last night

January 17, 2018
Confirming earlier computational models, researchers at University of California San Diego and UC San Diego School of Medicine, with colleagues in Arizona and Louisiana, report that episodic memories are encoded in the hippocampus ...

Recording a thought's fleeting trip through the brain

January 17, 2018
University of California, Berkeley neuroscientists have tracked the progress of a thought through the brain, showing clearly how the prefrontal cortex at the front of the brain coordinates activity to help us act in response ...

Midbrain 'start neurons' control whether we walk or run

January 17, 2018
Locomotion comprises the most fundamental movements we perform. It is a complex sequence from initiating the first step, to stopping when we reach our goal. At the same time, locomotion is executed at different speeds to ...

Miles Davis is not Mozart: The brains of jazz and classical pianists work differently

January 16, 2018
Keith Jarret, world-famous jazz pianist, once answered in an interview when asked if he would ever be interested in doing a concert where he would play both jazz and classical music: "No, that's hilarious. [...] It's like ...

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.