Navigation Links
Exercise increases brain growth factor and receptors, prevents stem cell drop in middle age

BETHESDA, Md. (Nov. 18, 2008) − A new study confirms that exercise can reverse the age-related decline in the production of neural stem cells in the hippocampus of the mouse brain, and suggests that this happens because exercise restores a brain chemical which promotes the production and maturation of new stem cells.

Neural stem cells and progenitor cells differentiate into a variety of mature nerve cells which have different functions, a process called neurogenesis. There is evidence that when fewer new stem or progenitor cells are produced in the hippocampus, it can result in impairment of the learning and memory functions. The hippocampus plays an important role in memory and learning.

The study, "Exercise enhances the proliferation of neural stem cells and neurite growth and survival of neuronal progenitor cells in dentate gyrus of middle-aged mice," was carried out by Chih-Wei Wu, Ya-Ting Chang, Lung Yu, Hsiun-ing Chen, Chauying J. Jen, Shih-Ying Wu, Chen-Peng Lo, Yu-Min Kuo, all of the National Cheng Kung University Medical College in Taiwan. The study appears in the November issue of the Journal of Applied Physiology, published by The American Physiological Society.

Rise in corticosterone or fall in nerve growth factor?

The researchers built on earlier studies that found that the production of stem cells in the area of the hippocampus known as the dentate gyrus drops off dramatically by the time mice are middle age and that exercise can slow that trend. In the current study, the researchers wanted to track these changes in mice over time, and find out why they happen.

One hypothesis the researchers investigated is that the age-related decline in neurogenesis is tied to a rise in corticosterone in middle age. Elevation of corticosterone has been associated with a drop in the production of new stem cells in the hippocampus.

The second hypothesis is that nerve growth factors -- which encourage new neural cell growth but which decrease with age -- account for the drop in neurogenesis. Specifically, the study looked at whether a decrease in brain-derived neurotrophic growth factor leads to a decline in new neural stem cells.

Variables studied

The researchers trained young (3 months), adult (7 months), early middle-aged (9 months), middle-aged (13 months) and old (24 months) mice to run a treadmill for up to one hour a day.

The study tracked neurogenesis, age, exercise, serum corticosterone levels and brain-derived neurotrophic factor (BDNF) and its receptor TrkB levels in the hippocampus. The researchers focused on middle age as a critical stage for the decline of neurogenesis in the mice.

As expected, the study found that neurogenesis drops off sharply in middle-aged mice. For example, the number of neural progenitor and mitotic (dividing) cells in the hippocampus of middle-aged mice was only 5% of that observed in the young mice.

The researchers also found that exercise significantly slows down the loss of new nerve cells in the middle-aged mice. They found that production of neural stem cells improved by approximately 200% compared to the middle-aged mice that did not exercise. In addition, the survival of new nerve cells increased by 170% and growth by 190% compared to the sedentary middle-aged mice. Exercise also significantly enhanced stem cell production and maturation in the young mice. In fact, exercise produced a stronger effect in younger mice compared to the older mice.

How does this happen?

Based on these results, it appears that nerve growth factor has more to do with these findings than the corticosterone:

  • The middle-aged exercisers had more brain-derived neurotrophic factor and its receptor, TrkB, compared to the middle-aged mice that did not exercise. This suggests that exercise promotes the production of brain-derived neurotrophic factor which, in turn, promotes differentiation and survival of new brain cells in the hippocampus.
  • Exercise did not change the basal level of serum corticosterone in middle-aged mice. This suggests that the reduction of neurogenesis during aging is not due to the drop in corticosterone levels.


Contact: Christine Guilfoy
American Physiological Society

Related biology news :

1. Previous abortions and exercise: Do they affect pregnancy?
2. Study may explain exercise-induced fatigue in muscular dystrophies
3. Recommendations for childrens exercise lacking say experts
4. During exercise, the human brain shifts into high gear on alternative energy
5. For insulin sensitive overweight patients, 1 session of exercise improves metabolic health
6. Exercise could be the hearts fountain of youth
7. Post-exercise caffeine helps muscles refuel
8. Brief, intense exercise benefits the heart
9. Mass. General study shows how exercise changes structure and function of heart
10. Exercise during pregnancy leads to a healthier heart in moms- and babies-to-be
11. Where college students live can impact their weight, eating and exercise habits
Post Your Comments:
(Date:4/15/2016)...  A new partnership announced today will help ... in a fraction of the time it takes ... life insurance policies to consumers without requiring inconvenient ... Diagnostics, rapid testing (A1C, Cotinine and HIV) and ... weight, pulse, BMI, and activity data) available at ...
(Date:4/14/2016)... Israel , April 14, 2016 ... Authentication and Malware Detection, today announced the appointment of ... assumed the new role. Goldwerger,s leadership appointment ... on the heels of the deployment of its platform ... BioCatch,s behavioral biometric technology, which discerns unique cognitive and ...
(Date:3/31/2016)... 2016   LegacyXChange, ... "Company") LegacyXChange is excited to release its ... to be launched online site for trading 100% guaranteed ... will also provide potential shareholders a sense of the ... an industry that is notorious for fraud. The video ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... Raleigh, NC (PRWEB) , ... June 27, 2016 ... ... have just published their findings on what they believe could be a new ... summary of the new research. Click here to read it now. ...
(Date:6/27/2016)... , June 27, 2016   Ginkgo Bioworks ... to industrial engineering, was today awarded as one ... selection of the world,s most innovative companies. Ginkgo ... scale for the real world in the nutrition, ... engineers work directly with customers including Fortune 500 ...
(Date:6/23/2016)... ... 23, 2016 , ... Mosio, a leader in clinical research ... Recruitment and Retention Tips.” Partnering with experienced clinical research professionals, Mosio revisits the ... tools, and strategies for clinical researchers. , “The landscape of how patients receive ...
(Date:6/23/2016)... , June 23, 2016 Houston ... with the Cy-Fair Sports Association to serve as ... the agreement, Houston Methodist Willowbrook will provide sponsorship ... and connectivity with association coaches, volunteers, athletes and ... with the Cy-Fair Sports Association and to bring ...
Breaking Biology Technology: