Navigation Links
Aging and longevity tied to specific brain region in mice
Date:7/28/2010

Researchers watched two groups of mice, both nearing the end of a two-day fast. One group was quietly huddled together, but the other group was active and alert. The difference? The second set of mice had been engineered so their brains produced more SIRT1, a protein known to play a role in aging and longevity.

"This result surprised us," says the study's senior author Shin-ichiro Imai, MD, PhD, an expert in aging research at Washington University School of Medicine in St. Louis. "It demonstrates that SIRT1 in the brain is tied into a mechanism that allows animals to survive when food is scarce. And this might be involved with the lifespan-increasing effect of low-calorie diets."

Imai explains that the mice with increased brain SIRT1 have internal mechanisms that make them use energy more efficiently, which helps them move around in search of food even after a long fast. This increased energy-efficiency could help delay aging and extend lifespan.

The research findings are published in the July 28 issue of the Journal of Neuroscience.

Imai's past research demonstrated that SIRT1 is at the center of a network that connects metabolism and aging. A form of the gene is found in every organism on earth. The gene coordinates metabolic reactions throughout the body and manages the body's response to nutrition. SIRT1 is activated under low-calorie conditions, which have been shown to extend the life spans of laboratory animals.

The researchers found that the key to the mice's extra activity lies in a small region of the brain called the hypothalamus, which controls basic life functions such as hunger, body temperature, stress response and sleep-wake cycles.

At the start of the research project, the study's lead author Akiko Satoh, PhD, a postdoctoral research associate in developmental biology, saw that mice on low-calorie diets had increased amounts of SIRT1 in specific regions of the hypothalamus and that neurons in the same regions were activated.

So the research team developed mice that continually produced higher amounts of SIRT1 in their brains to see what the effect would be. That's when Satoh observed the mice's unusual level of activity under fasting conditions.

"This is the first time that it has been demonstrated that SIRT1 is a central mediator for behavior adaptation to low-calorie conditions," Satoh says.

Interestingly, these mice, called BRASTO (brain-specific SIRT1-overexpressing) mice, also maintained higher body temperatures after a 48-hour fast than ordinary mice, which experience a drop in body temperature during fasting.

"The BRASTO mice have a better capability to come up with energy to achieve a higher body temperature and increased activity level when food is restricted," says Imai, associate professor of developmental biology and of medicine.

The team also examined mice that had no ability to produce SIRT1 in their brains. During diet-restricting conditions, these mice did not increase their activity, and their body temperature dropped more than normal, giving further evidence that SIRT1 was essential for high-activity, high-temperature responses.

As the researchers looked further into the role of SIRT1 in the hypothalamus, they found that during diet restriction, SIRT1 enhanced the production of a specific neural receptor in the hypothalamus involved in regulating metabolic rate, food intake and insulin sensitivity. Furthermore, mice with increased brain SIRT1 had a higher neural response to the gut hormone, ghrelin, which is known to stimulate the hypothalamus during low-calorie conditions. Both findings add weight to a significant role for SIRT1 in the hypothalamic response to a restricted diet.

The scientists are continuing to study the BRASTO mice to see if they live longer than ordinary mice.

Their work suggests that the brain, and particularly the hypothalamus, might play a dominant role in governing the pace of aging. They believe their studies could eventually provide clues for increasing productive aging in people.

"If we can enhance the function of the human hypothalamus by manipulating SIRT1, we could potentially overcome some health problems associated with aging," Imai says. "One example is anorexia of aging in which elderly people lose the drive to eat. It is possible that enhancing SIRT1 could alleviate behavioral problems like this."


'/>"/>

Contact: Judy Martin Finch
martinju@wust.edu
314-286-0105
Washington University School of Medicine
Source:Eurekalert  

Related medicine news :

1. Neuroimaging study may pave way for effective Alzheimers treatments
2. SNMs Conjoint Mid-Winter Meetings continue to advance molecular imaging
3. Medical Imaging Northwest Completes Phase I of Its Healthcare IT Integration to Maintain Patient Care Improvements
4. Less is more in cancer imaging
5. Imaging manufacturers: Plan to reduce unnecessary radiation exposure and medical errors
6. National Council on Aging Releases Survey on Medical Imaging Safety
7. Statement from Larry Minnix, President & CEO, American Association of Homes and Services for the Aging, on President Obamas Health Care Reform Proposal
8. Sytropin HGH Shows Promising Anti-Aging Results
9. Artists, Product Designers, Printing Gurus, Game Developers, Manufacturing Engineers Will Converge at RAPID 2010/3D IMAGING Conference/Expo, May 18-20 in LA
10. WellNet Supports HPM Institute Director in Calling for More Active Enterprise Involvement in Managing Healthcare Quality and Costs
11. Proton beam therapy shows encouraging long-term outcome for patients with locally advanced sinonasal cancers
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Aging and longevity tied to specific brain region in mice
(Date:6/25/2016)... TX (PRWEB) , ... June 25, 2016 , ... Austin ... of the American College of Mohs Surgery and to Dr. Russell Peckham for medical ... and highly effective treatment for skin cancer. The selective fellowship in Mohs Micrographic Surgery ...
(Date:6/25/2016)... ... June 25, 2016 , ... "With 30 hand-drawn hand gesture animations, FCPX users ... - CEO of Pixel Film Studios. , ProHand Cartoon’s package transforms over 1,300 ... Pro X . Simply select a ProHand generator and drag it above media or ...
(Date:6/25/2016)... ... 25, 2016 , ... As a lifelong Southern Californian, Dr. Omkar Marathe earned ... the David Geffen School of Medicine at UCLA. He trained in Internal Medicine at ... fellowship in hematology/oncology at the UCLA-Olive View-Cedars Sinai program where he had the opportunity ...
(Date:6/25/2016)... ... 2016 , ... On Friday, June 10, Van Mitchell, Secretary of the Maryland ... iHire in recognition of their exemplary accomplishments in worksite health promotion. , The Wellness ... & Wellness Symposium at the BWI Marriott in Linthicum Heights. iHire was one of ...
(Date:6/24/2016)... ... , ... A recent article published June 14 on E Online ... on to state that individuals are now more comfortable seeking to undergo not only ... calf and cheek reduction. The Los Angeles area medical group, Beverly Hills Physicians (BHP) ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... DUBLIN , June 23, 2016 ... "Global MEMS Devices Medical Market Analysis 2016 - Forecast to ... The report contains up to date financial ... reliable analysis. Assessment of major trends with potential impact on ... dive analysis of market segmentation which comprises of sub markets, ...
(Date:6/23/2016)... , June 23, 2016 Research ... Pharma News Issue 52" report to their offering. ... in influenza treatment creates a favourable commercial environment for MedImmune ... growing patient base that will serve to drive considerable growth ... vaccine would serve to cap sales considerably, but development is ...
(Date:6/23/2016)... , , , WHEN: ... , , , , LOCATION: , , , Online, with ... , EXPERT PANELISTS:  , , , Frost & Sullivan,s Global Vice ... Senior Industry Analyst, Divyaa Ravishankar and Unmesh Lal, Program Manager , ... industry is witnessing an exceptional era. Several new demand spaces, such ...
Breaking Medicine Technology: