Navigation Links
Brain stem cells can be awakened, say Schepens scientists
Date:6/6/2008

Boston, MAScientists at Schepens Eye Research Institute have identified specific molecules in the brain that are responsible for awakening and putting to sleep brain stem cells, which, when activated, can transform into neurons (nerve cells) and repair damaged brain tissue. Their findings are published online this week in the Proceedings of the National Academy of Science (PNAS).

An earlier paper (published in the May issue of Stem Cells) by the same scientists laid the foundation for the PNAS study findings by demonstrating that neural stem cells exist in every part of the brain, but are mostly kept silent by chemical signals from support cells known as astrocytes.

"The findings from both papers should have a far-reaching impact," says principal investigator, Dr. Dong Feng Chen, who is an associate scientist at Schepens Eye Research Institute and an assistant professor of ophthalmology at Harvard Medical School. Chen believes that tapping the brain's dormant, but intrinsic, ability to regenerate itself is the best hope for people suffering from brain-ravaging diseases such as Parkinson's or Alzheimer's disease or traumatic brain or spinal cord injuries.

Until these studies, which were conducted in the adult brains of mice, scientists assumed that only two parts of the brain contained neural stem cells and could turn them on to regenerate brain tissue-- the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ). The hippocampus is responsible for learning and memory, while the SVZ is a brain structure situated throughout the walls of lateral ventricles (part of the ventricular system in the brain) and are responsible for generating neurons reponible for smell. So scientists believed that when neurons died in other areas of the brain, they were lost forever along with their functions.

In the first study, Chen's team learned that stem cells existed everywhere in the brain by testing tissue from different parts of adult mice brains in cultures containing support cells (known as astrocytes) from the hippocampus, where stem cells do regenerate. In the cultures the stem cells from other brain regions came to life and turned into neurons.

When they compared the chemical makeup of the areas known to generate new neurons in the hippocampus with other parts of the brain, the team discovered that astrocytes in the hippocampus were sending one signal to the stem cells and that those from the rest of the brain were sending a different signal to stem cells.

In the second (PNAS) study, the team went on to discover the exact nature of those different chemical signals. They learned that in the areas where stem cells were sleeping, atrocytes were producing high levels of two related molecules--ephrin-A2 and ephrin-A3. They also found that removing these molecules (with a genetic tool) activated the sleeping stem cells.

The team also found that astrocytes in the hippocampus produce not only much lower levels of ephrin-A2 and ephrin-3, but also release a protein named sonic hodghoc that, when added in culture or injected into the brain, stimulates neural stem cells to divide and become new neurons.

"These findings identify a key pathway that controls neural stem cell growth in the adult brain and suggest that it may be possible to reactivate the dormant regenerative potential by adding sonic hedgehoc, or blocking ephrin-A2 or ephrin-A3," says Dr. Jianwei Jiao, the first author of the two papers,

The next step for the team will be to stimulate the sleeping stem cells in animals who are models of neurodegenerative disorders, such as Parkinson's disease, to see if the brains can repair themselves and restore their damaged functions.


'/>"/>
Contact: Patti Jacobs
pjacobs12@comcast.net
617-864-2712
Schepens Eye Research Institute
Source:Eurekalert

Related biology news :

1. Scientists discover a molecular scaffold that guides connections between brain cells
2. Green tea compounds beat OSA-related brain deficits
3. Researchers uncover mechanism of action of antibiotic able to reduce neuronal cell death in brain
4. NJIT applauds students for studies on brain injury, glaucoma and more
5. Decoding the dictionary: Study suggests lexicon evolved to fit in the brain
6. Its a unisex brain with specific signals that trigger male behavior
7. Detecting dangerous chemicals with lasers, exploring the brains circuitry with light and more
8. Vitamin D in brain function
9. Unconscious decisions in the brain
10. Brain study may lead to improved epilepsy treatments
11. Learning and the brain
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/11/2017)... 11, 2017 Crossmatch®, a globally-recognized leader ... today announced that it has been awarded a ... Activity (IARPA) to develop next-generation Presentation Attack Detection ... "Innovation has been a driving force within Crossmatch ... allow us to innovate and develop new technologies ...
(Date:4/11/2017)... NXT-ID, Inc. (NASDAQ:   NXTD ) ("NXT-ID" or ... independent Directors Mr. Robin D. Richards and Mr. ... the company,s corporate governance and expertise. ... Gino Pereira , Chief Executive Officer said," ... and benefiting from their considerable expertise as we move forward ...
(Date:4/5/2017)... April 5, 2017 Today HYPR Corp. ... the server component of the HYPR platform is officially ... the end-to-end security architecture that empowers biometric authentication across ... has already secured over 15 million users across the ... of connected home product suites and physical access represent ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... , ... October 12, 2017 , ... ... Vilnius, Lithuania, announced today that they have entered into a multiyear collaboration to ... provide CRISPR researchers with additional tools for gene editing across all applications. , ...
(Date:10/11/2017)... (PRWEB) , ... October 11, 2017 , ... ... Foundation President Andi Purple announced Dr. Suneel I. Sheikh, the co-founder, CEO ... ASTER Labs ), Inc. has been selected for membership in ARCS Alumni ...
(Date:10/11/2017)... BioMarketing, a leading provider of patient support solutions, has announced ... network, which will launch this week. The VMS CNEs will ... to enhance the patient care experience by delivering peer-to-peer education ... professionals to help women who have been diagnosed and are ... ...
(Date:10/10/2017)... ... October 10, 2017 , ... San Diego-based team building and ... rebranding initiative announced today. The bold new look is part of a transformation ... moves into a significant growth period. , It will also expand its service offering ...
Breaking Biology Technology: