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:3/9/2016)... , March 9, 2016  Crossmatch ® , ... enrollment solutions, today announced the addition of smart ... Altus multi-factor authentication platform. New contextual and ... to step-up security where it,s needed most — ... Washington, DC . --> ...
(Date:3/3/2016)... SOTO, Kansas , March 3, 2016 ... Oncimmune,s Early CDT®-Lung, a blood test to aid ... cancer Early CDT®-Lung test to its clients ... Early CDT®-Lung test to its clients which include ... a leader in early cancer detection, today announced a ...
(Date:3/1/2016)... FRANCISCO , March 1, 2016  (RSAC Booth ... year, but a whopping $118 billion is lost to ... to overzealous and inaccurate fraud detection. At the RSA ... in the way companies handle authentication by devaluing the ... and behavioral analytics. --> ...
Breaking Biology News(10 mins):
(Date:4/29/2016)... , ... April 29, 2016 , ... Summit for Stem ... support the development of a patient-specific stem cell therapy for the treatment of Parkinson’s ... of Dr. Jeanne Loring at The Scripps Research Institute in San Diego, CA. ...
(Date:4/28/2016)... 2016 Q BioMed Inc. ... CEO  was featured in an article he wrote ... Fear To Tread: http://www.lifescienceleader.com/doc/accelerators-enter-when-vcs-fear-to-tread-0001 ... is an essential business journal for life science ... to Big Pharmas. Their content is designed to ...
(Date:4/28/2016)... ... April 28, 2016 , ... Morris Midwest ... house for regional manufacturers at its Maple Grove, Minnesota technical center, May 11-12. ... Chiron and Trumpf. Almost 20 leading suppliers of tooling, accessories, software and ...
(Date:4/27/2016)... ... April 27, 2016 , ... Most consumers engage ... fingerprint recognition for secure access, voice recognition for hands-free communication, and facial recognition ... interacting with biometrics technology today. But if they asked Joey Pritikin, Vice ...
Breaking Biology Technology: