Navigation Links
Brain structure adapts to environmental change
Date:6/13/2011

  • Hippocampus adapts to environmental stresses
  • Stockpiles neuronal stem cells under deprived conditions, produces more neurons under favorable conditions
  • Knowledge of how neural stem cells produce neurons could lead to potential treatment for neurodegenerative diseases such as Alzheimer's and Parkinson's

(NEW YORK, NY, June 13, 2011) Scientists have known for years that neurogenesis takes place throughout adulthood in the hippocampus of the mammalian brain. Now Columbia researchers have found that under stressful conditions, neural stem cells in the adult hippocampus can produce not only neurons, but also new stem cells. The brain stockpiles the neural stem cells, which later may produce neurons when conditions become favorable. This response to environmental conditions represents a novel form of brain plasticity. The findings were published online in Neuron on June 9, 2011.

The hippocampus is involved in memory, learning, and emotion. A research team led by Alex Dranovsky, MD, PhD, assistant professor of clinical psychiatry at Columbia University Medical Center and research scientist in the Division of Integrative Neuroscience at the New York State Psychiatric Institute/Columbia Psychiatry, compared the generation of neural stem cells and neurons in mice housed in isolation and in mice housed in enriched environments. They then used lineage studies, a technique that traces stem cells from their formation to their eventual differentiation into specific cell types, to see what proportion of neural stem cells produced neurons.

Deprived and enriched environments had opposite effects. The brains of the socially isolated mice accumulated neural stem cells but not neurons. The brains of mice housed in enriched environments produced far more neurons, but not more stem cells. The average mouse dentate gyrus, the area of the hippocampus where neurogenesis takes place, has about 500,000 neurons; the enriched environment caused an increase of about 70,000 neurons.

"We already knew that enriching environments are neurogenic, but ours is the first report that neural stem cells, currently thought of as 'quiescent,' can accumulate in the live animal," said Dr. Dranovsky. "Since this was revealed simply by changing the animal's living conditions, we think that it is an adaptation to stressful environments. When conditions turn more favorable, the stockpiled stem cells have the opportunity to produce more neuronsa form of 'neurons on demand.'"

The researchers also looked at neuronal survival. They found that social isolation did not cause it to decrease. Scientists already knew that environmental enrichment increased neuronal survival―further increasing the neuron population.

To a lesser extent, location within the hippocampus affected whether stem cells became neurons. While the ratio of stem cells to neurons remained constant in the lower blade of the dentrate gyrus, it varied in the upper blade.

Age also affected the results. After three months, the brains of the isolated mice stopped accumulating neural stem cells. But the mice in enriched environments continued to produce more neurons.

Dranovsky and his team now want to see whether this hippocampal response is specific to social isolation or is a more general response to stress. Another question is whether all neural stem cells have the same potential to produce neurons.

"The long-term goal." Said Dr. Dranovsky, "is to figure out how to instruct neural stem cells to produce neurons or more stem cells. This could lead to the eventual use of stem cells in neuronal replacement therapy for neurodegenerative diseases and other central nervous system conditions."


'/>"/>

Contact: Ann Rae Jonas
arj2116@columbia.edu
212-305-6535
Columbia University Medical Center
Source:Eurekalert

Related biology news :

1. Birdsong independent of brain size
2. Emerging research in brain connectivity reveals new understanding of neurological disorders
3. New neurons take 6 months or more to mature in non-human primate brain
4. Deciding to stay or go is a deep-seated brain function
5. Early light refines the brains circuitry for vision
6. Changes in brain circuitry play role in moral sensitivity as people grow up
7. Pitt team recreates brain cell networks with new view of activity behind memory formation
8. What doesnt kill the brain makes it stronger
9. High iron, copper levels block brain-cell DNA repair
10. Building brains: An introduction to neural development
11. Surprising findings from studies of spontaneous brain activity
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/23/2017)... ITHACA, N.Y. , June 23, 2017  IBM ... in dairy research, today announced a new collaboration using ... the chances that the global milk supply is impacted ... project, Cornell University has become the newest academic institution ... Chain, a food safety initiative that includes IBM Research, ...
(Date:5/6/2017)... , May 5, 2017 ... just announced a new breakthrough in biometric authentication ... exploits quantum mechanical properties to perform biometric authentication. These ... smart semiconductor material created by Ram Group and ... finance, entertainment, transportation, supply chains and security. Ram ...
(Date:4/13/2017)... April 13, 2017 UBM,s Advanced Design and ... will feature emerging and evolving technology through its 3D ... will run alongside the expo portion of the event ... and demonstrations focused on trending topics within 3D printing ... and manufacturing event will take place June 13-15, 2017 at ...
Breaking Biology News(10 mins):
(Date:10/7/2017)... ... October 06, 2017 , ... ... providing advanced instruments and applications consulting for microscopy and surface analysis, Nanoscience ... application consulting, Nanoscience Analytical offers a broad range of contract analysis services ...
(Date:10/7/2017)...  The 2017 Nobel Prize in Chemistry recognizes ... Joachim Frank and Richard Henderson ... (cryo-EM) have helped to broaden the use ... The winners worked with systems manufactured by Thermo ... resolved, three-dimensional images of protein structures that lead ...
(Date:10/6/2017)... Washington, D.C. (PRWEB) , ... October 06, 2017 ... ... Cure) will host a lunch discussion and webinar on INSIGhT, the first-ever adaptive ... INSIGhT Principal Investigator, Dana-Farber Cancer Institute. The event is free and open to ...
(Date:10/5/2017)... ... 2017 , ... Understanding the microbiome, the millions of bacteria that live in ... Are My Future, the newest exhibit on display at the University City Science Center’s ... through the lens of the gut microbiome. , Gut Love opens October 12, ...
Breaking Biology Technology: