Featured Research

from universities, journals, and other organizations

Exercise, surgically removing belly fat improves cognition in obese, diabetic mice

Date:
February 26, 2014
Source:
Medical College of Georgia at Georgia Regents University
Summary:
Cognitive decline that often accompanies obesity and diabetes can be reversed with regular exercise or surgical removal of belly fat, scientists report. A drug already used to treat rheumatoid arthritis also helps obese/diabetic adult mice regain their ability to learn and comprehend, while transplanting belly fat to a normal mouse reduces those abilities. Studies in humans and animals indicate that obesity and diabetes -- which often go hand in hand -- essentially triple the risk of mild cognitive impairment as well as Alzheimer's.

Cognitive decline that often accompanies obesity and diabetes can be reversed with regular exercise or surgical removal of belly fat, scientists report. A drug already used to treat rheumatoid arthritis also helps obese/diabetic adult mice regain their ability to learn and comprehend, while transplanting belly fat to a normal mouse reduces those abilities, said Dr. Alexis M. Stranahan (pictured), neuroscientist at the Medical College of Georgia at Georgia Regents University.
Credit: Phil Jones, Georgia Regents University

Cognitive decline that often accompanies obesity and diabetes can be reversed with regular exercise or surgical removal of belly fat, scientists report.

Related Articles


A drug already used to treat rheumatoid arthritis also helps obese/diabetic adult mice regain their ability to learn and comprehend, while transplanting belly fat to a normal mouse reduces those abilities, said Dr. Alexis M. Stranahan, neuroscientist at the Medical College of Georgia at Georgia Regents University.

Studies in humans and animals indicate that obesity and diabetes -- which often go hand in hand -- essentially triple the risk of mild cognitive impairment as well as Alzheimer's. Stranahan focused on the effect of fat- and diabetes-associated inflammation in the brain's hippocampus, the center of learning and memory.

"These obese diabetic mice have very high levels of inflammatory cytokines and I think it's because their bodies are reacting to the invasion of fat into tissues where it does not belong," said Stranahan, corresponding author of the study in The Journal of Neuroscience. "It's almost as if the fat were an external pathogen."

Cytokines are major components of an immune response that typically targets invaders such as viruses. "They kind of mobilize all the natural killer cells and macrophages to kill off whatever is causing the pathogenic environment," Stranahan said. After clearing debris or danger, cytokine levels should subside. However in obesity, fat appears viewed as a chronic invader that keeps levels of interleukin-1 beta and inflammation high.

Like a perfect storm, obesity also weakens the protective blood-brain barrier, easing access of high interleukin-1 beta levels to the brain.

Inside the brain, interleukin-1 beta turns normally supportive microglial cells predatory. Microglia typically scarf up trash and infectious agents in the brain but when interleukin-1 beta binds to their receptors, microglia signal neurons to malfunction. Microglia then consume neuronal synapses, the major points of communication between brain cells. "This interleukin-1 beta signal makes them predatory. They eat them up," Stranahan said.

Exercise and surgery lower levels of the troublemaker in the body, so it doesn't affect the brain while the cytokine antagonist sequesters interleukin-1 beta so it can't reach receptors on the neurons or microglia.

While exercise is likely the best strategy, Stranahan suspects that this type of pharmacological intervention could also help patients who can't exercise, such as the frail and elderly. Liposuction likely is not a viable solution since scientists removed 15 to 20 percent of the mouse's body weight, far more fat than typical liposuction in humans.

Interestingly, Stranahan's previous studies have shown that healthy mice, which may run five to 10 kilometers weekly on running wheels, dropped to a fraction of that activity level as they got fat.

"They stop voluntarily exercising once they start to become obese," she said. Pushing fat mice to resume normal activity for three months, reduced obesity and brain inflammation and helped repair synaptic dysfunction. In fact, treadmill-trained and normal mice performed indistinguishably on spatial and object recognition tests.

Next steps include similar studies in a diet-induced obesity model instead of the single-gene alteration that produced the animal model for this study. The single genetic change desensitized the mice to the satiety hormone leptin so they always wanted to eat. In fact, even the mice that exercised and had surgery, continued to overeat.

Most human obesity is caused by overeating, inactivity, and possibly a genetic predisposition involving more than one gene. Early data indicates that it takes over-fed mice longer to get fat and show signs of cognitive impairment than their genetically altered counterparts, Stranahan said. But, again, the damage appears reversible.


Story Source:

The above story is based on materials provided by Medical College of Georgia at Georgia Regents University. Note: Materials may be edited for content and length.


Journal Reference:

  1. J. R. Erion, M. Wosiski-Kuhn, A. Dey, S. Hao, C. L. Davis, N. K. Pollock, A. M. Stranahan. Obesity Elicits Interleukin 1-Mediated Deficits in Hippocampal Synaptic Plasticity. Journal of Neuroscience, 2014; 34 (7): 2618 DOI: 10.1523/JNEUROSCI.4200-13.2014

Cite This Page:

Medical College of Georgia at Georgia Regents University. "Exercise, surgically removing belly fat improves cognition in obese, diabetic mice." ScienceDaily. ScienceDaily, 26 February 2014. <www.sciencedaily.com/releases/2014/02/140226095254.htm>.
Medical College of Georgia at Georgia Regents University. (2014, February 26). Exercise, surgically removing belly fat improves cognition in obese, diabetic mice. ScienceDaily. Retrieved October 31, 2014 from www.sciencedaily.com/releases/2014/02/140226095254.htm
Medical College of Georgia at Georgia Regents University. "Exercise, surgically removing belly fat improves cognition in obese, diabetic mice." ScienceDaily. www.sciencedaily.com/releases/2014/02/140226095254.htm (accessed October 31, 2014).

Share This



More Health & Medicine News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

U.S. Ebola Response Measures Demonstrated

U.S. Ebola Response Measures Demonstrated

AP (Oct. 31, 2014) Officials in the Washington area showed off Ebola response measures being taken at Dulles International Airport and the National Institutes of Health. (Oct. 31) Video provided by AP
Powered by NewsLook.com
Fauci Says Ebola Risk in US "essentially Zero"

Fauci Says Ebola Risk in US "essentially Zero"

AP (Oct. 30, 2014) NIAID Director Anthony Fauci said the risk of Ebola becoming an epidemic in the U.S. is essentially zero Thursday at the Washington Ideas Forum. He also said an Ebola vaccine will be tested in West Africa in the next few months. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Nurse Defies Ebola Quarantine With Bike Ride

Nurse Defies Ebola Quarantine With Bike Ride

AP (Oct. 30, 2014) A nurse who vowed to defy Maine's voluntary quarantine for health care workers who treated Ebola patients followed through on her promise Thursday, leaving her home for an hour-long bike ride. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Pot-Infused Edibles Raise Concerns in Colorado

Pot-Infused Edibles Raise Concerns in Colorado

AFP (Oct. 30, 2014) Colorado may have legalized marijuana for recreational use, but the debate around the decision still continues, with a recent - failed - attempt to ban cannabis-infused edibles. Duration: 01:53 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins