(Press-News.org) This release is available in German.
Neural stem cells can do a lot, but not everything. For example, brain and spinal cord cells are not usually generated by neural stem cells of the peripheral nervous system, and it is not possible to produce cells of the peripheral nervous system from the stem cells of the brain. However, researchers from the Max Planck Institute for Brain Research in Frankfurt and the Max Planck Institute of Immunobiology and Epigenetics in Freiburg have now succeeded in producing central nervous system cells from neural stem cells of the peripheral nervous system. They found that if peripheral stem cells are maintained under defined growth conditions, they generate oligodendrocytes, which form the myelin layer that surrounds the neurons found in the brain and spinal cord.
The mammalian nervous system consists of a central (brain, spinal cord) and peripheral nervous system (e.g. nerves and sensory ganglia). Although the two systems are very closely interlinked, they differ anatomically and consist of different cell types. The cell types of the peripheral nervous system originate from precursor cells in the embryo called the neural crest. To date, it was believed that these neural crest stem cells could generate the neurons and support cells, known as glial cells, of the peripheral nervous system, but not the cells of the central nervous system.
Environmental conditions clearly determine the kind of cells into which the neural crest stem cells develop. Together with colleagues from Paris, the Freiburg- and Frankfurt-based scientists succeeded in demonstrating that, under modified conditions, these stem cells can also generate cells of the central nervous system. They exposed stem cells from the peripheral nervous system of embryonic or postnatal mice to different culture conditions. In addition to neurons, the neural crest stem cells also developed into different types of glial cells of the central nervous system, including oligodendrocytes and astrocytes. "The culture medium reprograms the neural crest stem cells in such a way that they change their identity. This worked without genetic modification of the cells," explains Hermann Rohrer from the Max Planck Institute for Brain Research.
Factors in the culture medium clearly activated a different genetic program so that cell types developed from the stem cells, which normally would not. The scientists do not yet understand the precise factors at work here. However, there are some indications that fibroblast growth factor (FGF) is involved in this transformation.
In the brains of mice at different developmental stages, the reprogrammed stem cells mainly developed into oligodendrocytes, which form the myelin layer around the neurons of the central nervous system and are, therefore, indispensable for the transmission of electrical stimuli. Transplantation experiments carried out by the researchers on genetically modified mice that do not produce myelin and have severe neurological defects proved that the new oligodendrocytes can also assume this task. "The reprogrammed stem cells can form cells of the central nervous system, and the new cells can permanently integrate into this system," says Verdon Taylor of the Max Planck Institute of Immunobiology and Epigenetics.
It is not yet clear, to what extent these basic research findings will contribute to the development of cell therapy for humans. This would require that similar stem cells are present and accessible in the peripheral nervous system of humans, and that these can be propagated and reprogrammed in culture. "At present, we only know that these stem cells in mice also have the potential to produce oligodendrocytes," says Hermann Rohrer. The scientists would now like to investigate in greater detail which molecular mechanisms are responsible for the reprogramming of the stem cells, whether neural crest stem cells also exist in the peripheral nervous system of adult mice and what kind of conditions are required to enable the reprogramming of these cells.
INFORMATION:
Original work:
Peripheral nervous system progenitors can be reprogrammed to produce myelinating oligodendrocytes and repair brain lesions
Ellen Binder, Marion Rukavina, Hessameh Hassani, Marlen Weber, Hiroko Nakatani, Tobias Reiff,
Carlos Parras, Verdon Taylor, and Hermann Rohrer
Journal of Neuroscience, April 27, 2011, DOI:10.1523/JNEUROSCI.0129-11.2011
A new program for neural stem cells
2011-05-13
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
New Rules on Whistleblower Retaliation for Nuclear and Environmental Complaints
2011-05-13
On January 18, 2011, the Occupational Safety and Health Administration (OSHA) published a rule establishing procedures for handling nuclear and environmental whistleblower retaliation complaints. This rule aligns retaliation complaints under the Energy Reorganization Act (ERA) of 1974 and the six environmental statutes with other OSHA whistleblower provisions. The rule allows employees to file oral or written complaints in English and other languages, making complaint filing more accessible to all employees.
The ERA provision serves to protect employees who are retaliated ...
Scientists suggest independent monitoring of deep-sea hydrocarbon industry
2011-05-13
Writing in the scientific journal Nature, scientists have called for increased discussion of independent monitoring of deep-sea hydrocarbon industry activity with the aim of obtaining a better understanding of its ecological impact.
The hydrocarbon industry is increasingly searching for hydrocarbon resources at much greater depths and developing drilling technology to exploit them. However, drilling the seafloor at great depths is technically very challenging and carries with it poorly known risks.
"The Deepwater Horizon disaster in the Gulf of Mexico last year and ...
Africa's sea turtles need passports for protection
2011-05-13
Satellite tracking of olive ridley sea turtles off the coast of Central Africa has revealed that existing protected areas may be inadequate to safeguard turtles from fishing nets, according to scientists with the University of California-Santa Cruz, the Wildlife Conservation Society, the University of Exeter, and others. Scientists involved in the study recommended the extension of an international marine park that spans the waters of Gabon and the Republic of Congo and better international cooperation to manage this threatened species.
The study was published May 11 ...
Choose the Personal Representative for Your Michigan Estate Carefully
2011-05-13
One of the most important persons in your life takes his or her most prominent role after your death. The personal representative of your estate will settle your affairs for you after you are gone. He or she -- or it, if you choose a bank or trust company to act for you -- will have the responsibility to see that the wishes you express in your will are carried out for the benefit of your beneficiaries.
In simple terms, your will is the legal document that gives you the opportunity to direct how the most important parts of your life will be wrapped up upon your demise. ...
No-Fault Divorce and Equitable Distribution of Property in New Jersey
2011-05-13
For the first time, in 2007, a new law allowed true no-fault divorce for couples with irreconcilable differences in New Jersey. Understanding the provisions of the state's no-fault divorce law and how marital property is divided among former spouses is essential for people undergoing or considering divorce in New Jersey.
New Jersey No-Fault Divorce
Under previous New Jersey law, a complaint for divorce had to state a specific ground for dissolving a marriage, such as extreme cruelty or separation. To obtain a divorce, one spouse had to allege that the other spouse ...
Dalhousie biologists interpret the language of sperm whales
2011-05-13
When they dive together, sperm whales make patterns of clicks to each other known as "codas". Recent findings suggest that, not only do different codas mean different things, but that whales can also tell which member of their community is speaking based on the sound properties of the codas. Just as we can tell our friends apart by the sounds of their voices and the way they pronounce their words, different sperm whales make the same pattern of clicks, but with different accents.
Caribbean and Pacific whales have different repertoires of codas, like a regional dialect, ...
Bleak memories of childhood
2011-05-13
Every year, between 3000 and 3500 children are physically abused in Germany. Many more, some 12,000 to 13,000, suffer sexual abuse. These are the figures from official criminal statistics, but in fact a high proportion of unreported cases is assumed for both offenses. The latest edition of Deutsches Ärzteblatt International contains an article in which Winfried Häuser of the Technical University of Munich and his co-authors present the findings of their representative survey of a sample of the German population, conducted with the goal of quantifying the true dimensions ...
Repealing the Texas Driver Responsibility Program: A Good Idea?
2011-05-13
In 2003, Texas implemented the Texas Driver Responsibility Program. The Texas legislature thought the program would be an optimal way to combat problems like drunk-driving accidents, and budget shortfalls. However, critics say the program has been a failure and are now urging the legislature to repeal the program.
What is the Texas Driver Responsibility Program?
The Texas Driver Responsibility Program requires drivers who accumulate points on their driver's license for certain traffic citations or who are convicted of certain traffic offenses to pay a fine known ...
Salinity in Outer Banks wells traced to fossil seawater
2011-05-13
DURHAM, N.C. – Rising salinity in the primary source for desalinated tap water in North Carolina's Outer Banks has been traced to fossil seawater, not – as some have feared – to recent seawater intrusion.
This means the saline groundwater in the Yorktown aquifer can remain a valuable source of desalination for decades to come, without Dare County communities having to switch to the much more costly alternative of desalinating seawater, says Duke University researcher Avner Vengosh.
Vengosh, professor of geochemistry and water quality at Duke's Nicholas School of the ...
Economist studies how higher gas prices affect consumer behavior
2011-05-13
A dollar is a dollar is a dollar, so goes the economic theory of fungibility. But do people really act that way? In a new working paper, Brown University economist Justine Hastings and Jesse Shapiro of Chicago Booth School of Business find striking evidence that basic consumer choice behavior violates this bedrock theory.
"Fungibility is an important assumption in many economic models, but we have a lot of laboratory evidence suggesting that people don't, in fact, treat a dollar as a dollar," said Hastings, associate professor of economics. "People instead try to manage ...