Researchers explain how neural stem cells create new and varied neurons

University of Oregon team finds stem cell patterns in flies offer potential applications for human biologists

2013-06-20

(Press-News.org) EUGENE, Ore. -- (June 19, 2013) – A new study examining the brains of fruit flies reveals a novel stem cell mechanism that may help explain how neurons form in humans. A paper on the study by researchers at the University of Oregon appeared in the online version of the journal Nature in advance of the June 27 publication date.

"The question we confronted was 'How does a single kind of stem cell, like a neural stem cell, make all different kinds of neurons?'" said Chris Doe, a biology professor and co-author on the paper "Combinatorial temporal patterning in progenitors expands neural diversity."

Researchers have known for some time that stem cells are capable of producing new cells, but the new study shows how a select group of stem cells can create progenitors that then generate numerous subtypes of cells.

"Instead of just making 100 copies of the same neuron to expand the pool, these progenitors make a whole bunch of different neurons in a particular way, a sequence," Doe said. "Not only are you bulking up the numbers but you're creating more neural diversity."

The study, funded by the Howard Hughes Medical Institute and the NIH National Institute of Child Health and Human Development, builds on previous research from the Doe Lab published in 2008. That study identified a special set of stem cells that generated neural progenitors. These so-called intermediate neural progenitors (INPs) were shown to blow up into dozens of new cells. The research accounted for the number of cells generated, but did not explain the diversity of new cells.

"While it's been known that individual neural stem cells or progenitors could change over time to make different types of neurons and other types of cells in the nervous system, the full extent of this temporal patterning had not been described for large neural stem cell lineages, which contain several different kinds of neural progenitors," said lead author Omar Bayraktar, a doctoral student in developmental neurobiology who recently defended his dissertation.

The cell types in the study, Bayraktar said, have comparable analogs in the developing human brain and the research has potential applications for human biologists seeking to understand how neurons form.

The Nature paper appears alongside another study on neural diversity by researchers from New York University. Together the two papers provide new insight into the processes involved in producing the wide range of nerve cells found in the brains of flies.

For their study, Bayraktar and Doe zeroed in on the stem cells in drosophila (fruit flies) known as type II neuroblasts. The neuroblasts, which had previously been shown to generate INPs, were shown in this study to be responsible for a more complex patterning of cells. The INPs were shown to sequentially generate distinct neural subtypes. The research accounted for additional neural diversity by revealing a second axis in the mechanism. Instead of making 100 neurons, as had been previously thought, a stem cell may be responsible for generating some 400 or 500 neurons.

The study concludes that neuroblasts and INP patterning act together to generate increased neural diversity within the central complex of the fruit fly and that progenitors in the human cerebral cortex may use similar mechanisms to increase neural diversity in the human brain. One long-term application of the research may be to eventually pinpoint stem cell treatments to target specific diseases and disorders.

"If human biologists understand how the different types of neurons are made, if we can tell them 'This is the pathway by which x, y and z neurons are made,' then they may be able to reprogram and redirect stem cells to make these precise neurons," Doe said.

The mechanism described in the paper has its limits. Eventually the process of generating new cells stops. One of the next questions to answer will be what makes the mechanism turn off, Doe said.

"This vital research will no doubt capture the attention of human biologists," said Kimberly Andrews Espy, vice president for research and innovation and dean of the UO graduate school. "Researchers at the University of Oregon continue to further our understanding of the processes that undergird development to improve the health and well-being of people throughout the world."

INFORMATION:

NIH grants to Doe (R01HD27056) and to Bayraktar (T32HD216345 and T32GM007413) supported the research, in addition to Howard Hughes Medical Institute support to Doe.

About the University of Oregon

The University of Oregon is among the 108 institutions chosen from 4,633 U.S. universities for top-tier designation of "Very High Research Activity" in the 2010 Carnegie Classification of Institutions of Higher Education. The UO also is one of two Pacific Northwest members of the Association of American Universities.

Media Contact: Lewis Taylor, associate director of PR and strategic communications, 541-346-2816, lewist@uoregon.edu

Links:

Related previous paper: http://www.neuro.uoregon.edu/doelab/pdfs2/Boone08.pdf

Doe Lab: http://uoneuro.uoregon.edu/doelab/

Like UO Science on Facebook: http://www.facebook.com/UniversityOfOregonScience

Follow UO Science on Twitter: https://twitter.com/UO_Research

Note: The University of Oregon is equipped with an on-campus television studio with a point-of-origin Vyvx connection, which provides broadcast-quality video to networks worldwide via fiber optic network. In addition, there is video access to satellite uplink, and audio access to an ISDN codec for broadcast-quality radio interviews.

ELSE PRESS RELEASES FROM THIS DATE:

Less is more: Novel cellulose structure requires fewer enzymes to process biomass to fuel

2013-06-20

LOS ALAMOS, N.M., June 19, 2013—Improved methods for breaking down cellulose nanofibers are central to cost-effective biofuel production and the subject of new research from Los Alamos National Laboratory (LANL) and the Great Lakes Bioenergy Research Center (GLBRC). Scientists are investigating the unique properties of crystalline cellulose nanofibers to develop novel chemical pretreatments and designer enzymes for biofuel production from cellulosic—or non-food—plant derived biomass. "Cellulose is laid out in plant cell walls as crystalline nanofibers, like steel reinforcements ...

A battery made of wood?

2013-06-20

A sliver of wood coated with tin could make a tiny, long-lasting, efficient and environmentally friendly battery. But don't try it at home yet– the components in the battery tested by scientists at the University of Maryland are a thousand times thinner than a piece of paper. Using sodium instead of lithium, as many rechargeable batteries do, makes the battery environmentally benign. Sodium doesn't store energy as efficiently as lithium, so you won't see this battery in your cell phone -- instead, its low cost and common materials would make it ideal to store huge amounts ...

Group-based child care is linked to reduced emotional problems in children of depressed mothers

2013-06-20

This news release is available in French. Child care is linked to fewer emotional problems and symptoms of social withdrawal among children exposed to maternal depression, according to a new study of nearly 2000 children conducted by researchers in Montreal, Canada, at the Sainte-Justine University Hospital Research Center, Université du Québec à Montréal (UQAM), and University of Montreal. "We found that children exposed to maternal depression during the preschool years were nearly two times more likely to develop emotional problems and separation anxiety symptoms. ...

Ibrutinib continues strong showing against mantle cell lymphoma

2013-06-20

HOUSTON - In a major international study led by researchers at The University of Texas MD Anderson Cancer Center, the targeted therapy ibrutinib continues to show remarkable promise for the treatment of relapsed or refractory mantle cell lymphoma (MCL). The most recent interim findings of the 18-center Phase 2 study were published today in the New England Journal of Medicine. Previous interim findings were presented in December 2012 at the 54th American Society of Hematology Annual Meeting and Exposition. Unprecedented results, fewer side effects "This oral inhibitor ...

Unexpected behavior of well-known catalysts

2013-06-20

Industrial palladium-copper catalysts change their structures before they get to work, already during the activation process. As a result, the reaction is catalysed by a catalyst that is different from the one originally prepared for it. This surprising discovery was made by researchers from the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw. Removing of nitrates from ground water or chlorine from dry cleaning wastes are important environmental protection operations that require the use of appropriate catalysts. Popular catalysts include well-known ...

Long-term study reports deep brain stimulation effective for most common hereditary dystonia

2013-06-20

LOS ANGELES (June 19, 2013) – In what is believed to be the largest follow-up record of patients with the most common form of hereditary dystonia – a movement disorder that can cause crippling muscle contractions – experts in deep brain stimulation report good success rates and lasting benefits. Michele Tagliati, MD, neurologist, director of the Movement Disorders Program at Cedars-Sinai Medical Center's Department of Neurology, and Ron L. Alterman, MD, chief of the Division of Neurosurgery at Beth Israel Deaconess Medical Center in Boston, published the study in the ...

Evolution of an outbreak: Complications from contaminated steroid injections

2013-06-20

(SACRAMENTO, Calif.) — A study of the patients who received injections of steroids contaminated with the fungus Exserohilum rostratum from the New England Compounding Center has found that some patients had fungal infections even though they did not experience a worsening of their symptoms and that magnetic resonance imaging (MRI) can help detect infection, especially among those individuals who received injections from highly contaminated lots. The study, along with an editorial by UC Davis Assistant Professor of Medical Microbiology and Immunology George R. Thompson, ...

Protected areas provide African birds with stepping stones to survival

2013-06-20

The protected area network in Tanzania is playing a vital role in the survival of savannah bird species as they move west in response to climate and environmental changes, according to new research led by the University of York. Using data on savannah birds from the Tanzanian Bird Atlas project - which has documented Tanzanian bird distributions over recent decades - the researchers found that they are using protected areas as stepping stones as they move to areas further west where dry seasons are getting longer, with movements of up to 300km noted. Much debate has centred ...

Danish chemists in molecular chip breakthrough

2013-06-20

Electronic components built from single molecules using chemical synthesis could pave the way for smaller, faster and more green and sustainable electronic devices. Now for the first time, a transistor made from just one molecular monolayer has been made to work where it really counts. On a computer chip. The molecular integrated circuit was created by a group of chemists and physicists from the Department of Chemistry Nano-Science Center at the University of Copenhagen and Chinese Academy of Sciences, Beijing. Their discovery "Ultrathin Reduced Graphene Oxide Films as ...

Black-white education gap is worsened by unresponsive state policymakers, Baylor study shows

2013-06-20

State policymakers' attention to teacher quality—an issue education research shows is essential to improving schooling outcomes for racial minority students—is highly responsive to low graduation rates among white students, but not to low graduation rates among black students, according to a Baylor University study. The findings are evidence that "the persisting achievement gap between white and black students has distinctively political foundations," the researchers wrote. The article, entitled "The Politic Foundations of the Black-White Education Achievement Gap," ...