Inflammation attacks brain's reward center

February 2, 2016
brain
Credit: public domain

A new study by Neil Harrison and colleagues published in Biological Psychiatry suggests that a brain reward center, the striatum, may be directly affected by inflammation and that striatal change is related to the emergence of illness behaviors.   

Inflammation increases the risk for .

More specifically, inflammation induces behavioral changes similar to depression that are often associated with illness, including , difficulty concentrating, lack of motivation, and reduced experience of pleasure.  

The authors recruited 23 patients with hepatitis C who were beginning treatment with interferon-alpha (INF-α). This treatment provokes an immediate inflammatory response, confirmed by measuring cytokines in the blood.  

Four hours after INF-α administration, a specialized type of imaging, called magnetization transfer imaging, was performed that showed evidence of microstructural changes in the when compared to scans conducted prior to INF-α administration. This suggests that the striatum is highly sensitive to IFN-α.  

IFN-α also induced fatigue and depression in the patients, particularly over weeks 4 through 12 of treatment. Interestingly, the early striatal structural change predicted the later emergence of fatigue, but not depression, in the study participants.  

Changes in the striatum were heterogeneous with some changes associated with the risk for fatigue, while other changes seemed to be protective against developing fatigue.  

"Inflammation-related fatigue and depression are big clinical problems," said Dr. John Krystal, Editor of Biological Psychiatry. "This study highlights that the brain regions central to reward and motivation are directly altered by inflammation in ways that that appear to predispose or protect against developing fatigue but not depression. The heterogeneous striatal response may suggest that fatigue and mood are supported by different microcircuits within the striatum."  

"These findings are important as they show that a relatively simple MRI technique can be used to measure effects of inflammation on the brain," Harrison commented. "Inflammation is increasingly implicated in the cause of common mental illnesses, particularly depression. This technique could be a powerful way to identify patients who are most sensitive to effects of on the brain. It could also be used to monitor response to novel anti-inflammatory therapies that are now being tested in depression."

Explore further: Inflammation linked to weakened reward circuits in depression

More information: Nicholas G. Dowell et al. Acute Changes in Striatal Microstructure Predict the Development of Interferon-Alpha Induced Fatigue, Biological Psychiatry (2016). DOI: 10.1016/j.biopsych.2015.05.015

Related Stories

Inflammation markers could guide depression treatments

January 12, 2016

Psychiatrists investigating depression have been energized in recent years by reports of rapid, successful treatment with drugs that interfere with the brain chemical glutamate, such as the anesthetic ketamine.

Uncovering the source of inflammatory malaise

October 22, 2012

(Medical Xpress)—A study conducted by researchers at Emory indicates that inflammation targets a part of the brain called the basal ganglia, causing symptoms of depression and fatigue. The study was recently reported in ...

Brain imaging reveals clues about chronic fatigue syndrome

May 23, 2014

A brain imaging study shows that patients with chronic fatigue syndrome may have reduced responses, compared with healthy controls, in a region of the brain connected with fatigue. The findings suggest that chronic fatigue ...

Recommended for you

Tough times make for more impulsive pre-teens

June 23, 2017

The loss of a grandparent. Marital discord at home. Trouble with peers. When pre-teens are forced to deal with adverse life events such as these they tend to become more impulsive in their decision-making later in life. And ...

Following a friend leads to unsafe driving behavior

June 23, 2017

Have you ever tried following a friend in a car? It can stressful; if you don't keep up, you are likely to get lost. To avoid this, you may make unsafe driving manoeuvres to keep sight of the car ahead.

Video games can change your brain

June 22, 2017

Scientists have collected and summarized studies looking at how video games can shape our brains and behavior. Research to date suggests that playing video games can change the brain regions responsible for attention and ...

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.