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:3/15/2016)... ALBANY, New York , March 15, 2016 ... a new market report published by Transparency Market Research "Digital ... Growth, Trends and Forecast 2015 - 2023," the global digital ... at US$ 731.9 Mn in 2014 and is forecast to ... to 2023. Growth of micro, small and medium enterprises (MSMEs) ...
(Date:3/14/2016)... 2016 http://www.apimages.com ) - ... - Renvoi : image disponible via AP Images ... --> DERMALOG, le leader de ... lecteurs d,empreintes digitales pour l,enregistrement des réfugiés en ... pour produire des cartes d,identité aux réfugiés. DERMALOG ...
(Date:3/10/2016)... 10, 2016 --> ... report "Identity and Access Management Market by Component (Provisioning, ... Governance), by Organization Size, by Deployment, by Vertical, and ... MarketsandMarkets, The market is estimated to grow from USD ... 2020, at a Compound Annual Growth Rate (CAGR) of ...
Breaking Biology News(10 mins):
(Date:5/25/2016)... ... May 25, 2016 , ... ... recently became double board-certified in surgery and surgery of the hand by the ... is no stranger to going above and beyond in his pursuit of providing ...
(Date:5/25/2016)... ... ... at the University of Athens say they have evidence that the variety of different ... lead to one good one. Surviving Mesothelioma has just posted an article on the ... 98 mesothelioma patients who got a second kind of drug therapy after ...
(Date:5/25/2016)... ... May 25, 2016 , ... Lady had been battling arthritis since ... ligament in her left knee. Lady’s owner Hannah sought the help of Dr Jeff ... surgeon, to repair her cruciate ligament and help with the pain of Lady’s arthritis. ...
(Date:5/24/2016)... ... May 24, 2016 , ... Cell therapies for ... be accelerated by research at Worcester Polytechnic Institute (WPI) that yielded a newly ... tissue regeneration. , The novel method, developed by WPI faculty members Raymond Page, ...
Breaking Biology Technology: