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VistaGen Secures Key U.S. Patent Covering Stem Cell Technology Methods Used to Test Drug Candidates for Liver Toxicity

Posted: April 26, 2012 at 5:10 am

SOUTH SAN FRANCISCO, CA--(Marketwire -04/25/12)- VistaGen Therapeutics, Inc. (VSTA.OB - News) (VSTA.OB - News), a biotechnology company applying stem cell technology for drug rescue, has secured a new United States patent covering the company's proprietary methods used to measure and type the toxic effects produced by drug compounds in liver stem cells.

Test methods included in this new patent, (U.S. Patent 11/445,733), titled "Toxicity Typing Using Liver Stem Cells," cover all mammalian liver stem cells -- rat and mouse cells, for example, in addition to human cells. Liver stem cells used in drug testing can be derived from in vivo tissue or produced from embryonic stem cells (ES) or induced pluripotent stem cells (iPS).

H. Ralph Snodgrass, Ph.D., VistaGen's President and Chief Scientific Officer, said, "This patent covers the monitoring of changes in gene expression as an assay for predicting drug toxicities. It is well known that drugs activate and suppress specific genes, and that the changes in gene expression reflect the mechanism of drug toxicities. The specific sets of genes that are affected become a profile of that drug."

VistaGen's new patent also covers techniques used to develop a database of gene expression profiles of drugs that have the same type of liver toxicity. Using sophisticated "pattern matching" database tools, drug developers can analyze these related profiles to determine "gene expression signatures" that are common and predictive of drugs that produce specific types of toxicity.

"Without this database capability, a drug's single gene expression profile could not be interpreted," Dr. Snodgrass added. "The ability to use liver stem cells to differentiate drug-dependent gene expression profiles, and to compare those profiles of drugs known to induce toxic liver effects, provides a powerful tool for predicting liver toxicity of new drug candidates, including drug rescue variants."

Shawn K. Singh, VistaGen's Chief Executive Officer, stated, "Strong and enforceable intellectual property rights are critical components of our plan to optimize the commercial potential of our Human Clinical Trials in a Test Tube platform. This new liver toxicity typing patent further solidifies our growing IP portfolio, and supports the continuing development of LiverSafe 3D, our human liver cell-based bioassay system, which complements our CardioSafe 3D human heart cell-based bioassay system for heart toxicity."

About VistaGen Therapeutics

VistaGen is a biotechnology company applying human pluripotent stem cell technology for drug rescue and cell therapy. VistaGen's drug rescue activities combine its human pluripotent stem cell technology platform, Human Clinical Trials in a Test Tube, with modern medicinal chemistry to generate new chemical variants (Drug Rescue Variants) of once-promising small-molecule drug candidates. These are drug candidates discontinued due to heart toxicity after substantial development by pharmaceutical companies, the U.S. National Institutes of Health (NIH) or university laboratories. VistaGen uses its pluripotent stem cell technology to generate early indications, or predictions, of how humans will ultimately respond to new drug candidates before they are ever tested in humans, bringing human biology to the front end of the drug development process.

Additionally, VistaGen's small molecule drug candidate, AV-101, is in Phase 1b development for treatment of neuropathic pain. Neuropathic pain, a serious and chronic condition causing pain after an injury or disease of the peripheral or central nervous system, affects approximately 1.8 million people in the U.S. alone. VistaGen is also exploring opportunities to leverage its current Phase 1 clinical program to enable additional Phase 2 clinical studies of AV-101 for epilepsy, Parkinson's disease and depression. To date, VistaGen has been awarded over $8.5 million from the NIH for development of AV-101.

Visit VistaGen at http://www.VistaGen.com, follow VistaGen at http://www.twitter.com/VistaGen or view VistaGen's Facebook page at http://www.facebook.com/VistaGen

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Leukaemia cells have a remembrance of things past

Posted: April 26, 2012 at 2:10 am

Public release date: 24-Apr-2012 [ | E-mail | Share ]

Contact: Dr Boris Kovacic Boris.Kovacic@vetmeduni.ac.at 43-125-077-5622 University of Veterinary Medicine -- Vienna

Although people generally talk about "cancer", it is clear that the disease occurs in a bewildering variety of forms. Even single groups of cancers, such as those of the white blood cells, may show widely differing properties. How do the various cancers arise and what factors determine their progression? Clues to these two issues, at least for leukaemias, have now been provided by Boris Kovacic and colleagues at the University of Veterinary Medicine, Vienna (Vetmeduni Vienna). The results are published in the current issue of the journal EMBO Molecular Medicine and have extremely important consequences for the treatment of a particularly aggressive type of leukaemia.

It is well known that many types of cancer arise as a result of a mutation within a cell and prevailing wisdom has held that the stage of differentiation of this cell determines exactly what form of cancer develops. For example, it was believed that so-called chronic myeloid leukaemia or CML arises from bone marrow stem cells, while a different type of leukaemia, known as B-cell acute lymphoid leukaemia or B-ALL, results from B-cell precursors. This belief has been spectacularly refuted by the latest results from Boris Kovacic and colleagues in the Vetmeduni Vienna's institutes of Animal Breeding and Genetics and of Pharmacology and Toxicology.

The researchers have now shown that both CML and B-ALL arise from the most primordial kind of blood cell (long-term haematopoietic stem cells), although the pathways by which the diseases progress are different. The usual causes of CML and B-ALL are two highly related versions of the same oncogene, BCR/ABL. If the primordial blood cells are transformed or made potentially cancerous by a particular version of BCR/ABL, for technical reasons termed BCR/ABLp210, the result is chronic myeloid leukaemia or CML. The long-term haematopoietic stem cells remain and act as the dreaded cancer stem cells, or CSCs, which ensure that the disease persists. Curing chronic myeloid leukaemia requires the complete elimination of the CSCs. However, if the long-term haematopoietic stem cells are transformed by a related version of BCR/ABL, BCR/ABLp185, the result is a highly aggressive form of leukaemia, B-ALL. The finding that B-ALL actually originates from the same stem cells as CML was both unexpected and highly provocative.

Kovacic and colleagues have shown further that B-ALL only develops if the transformed stem cell is exposed to a particular growth factor, interleukin-7. If interleukin-7 is present (it usually is), the transformed long-term haematopoietic stem cells undergo a differentiation step to CSCs, which in this case correspond to pro-B cells. If interleukin-7 is absent during the initial phase of transformation, B-ALL cannot develop.

In other words, two distinct types of cell are involved in leukaemia development, the primordial cells (also termed the cells of origin of cancer) and the cancer stem cells that cause the disease to progress. Unless the CSCs are eliminated, fresh cancer cells can arise at any time and the leukaemia will recur. The problem is that current leukaemia therapies are not designed to target CSCs. The primordial CSCs in CML are highly quiescent and thus difficult to target. In contrast, the CSCs in B-ALL are abundant and have a high turnover rate, which makes them susceptible to treatment. Treatment of B-ALL may thus succeed in eliminating most CSCs but if even a single cell remains intact it is likely that the patient will relapse, possibly with an even more aggressive form of leukaemia. "A therapy that targets the bulk of tumour cells will not work," as Kovacic succinctly summarizes his results. "To treat B-ALL successfully it will be necessary for us to learn much more about the development of the disease. A combined therapy is required, so future work should aim at developing drugs that target the long-term haematopoietic stem cells from which B-ALL is derived."

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The paper "Diverging fates of cells of origin in acute and chronic leukemia" by Boris Kovacic, Andrea Hoelbl, Gabriele Litos, Memetcan Alacakaptan, Christian Schuster, Katrin M. Fischhuber, Marc A. Kerenyi, Gabriele Stengl, Richard Moriggl, Veronika Sexl and the late Hartmut Beug is published in the current issue of the journal "EMBO Molecular Medicine" (2012, Vol. 4 pp. 283-297).

The work was initiated at the Research Institute of Molecular Pathology (IMP) and was performed together with groups at the Medical University of Vienna and the Ludwig Boltzmann Institute for Cancer Research in Vienna.

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Programming Highlights: American Association of Anatomists Annual Meeting

Posted: April 25, 2012 at 10:13 pm

EMBARGOED UNTIL PRESENTATION TIMES

PROGRAMMING HIGHLIGHTS: AMERICAN ASSOCIATION OF ANATOMISTS ANNUAL MEETING

Newswise The American Association of Anatomists will gather this week for its annual meeting in conjunction with the Experimental Biology 2012 conference, which will draw more than 14,000 scientists from industry, government and academia. Below are some programming highlights for the anatomy meeting. All presentations will be made at the San Diego Convention Center.

Stem cells derived from breast milk that behave like embryonic stem cells

Scientists in Australia have discovered that human breast milk contains stem cells that behave very much like embryonic stem cells. These breast-milk-derived, embryonic-like stem cells are able to turn into various body cell types, including bone, fat, liver, pancreatic and brain cells. Because breast milk is plentiful and can be accessed noninvasively and ethically, this discovery opens new avenues for exploration of innovative stem-cell therapies. Also, breast milk stem cells can be used as a physiological model to study malignant transformation that occurs in breast cancer, and therefore the findings may set the basis for research into new treatments for this disease. The group is now trying to understand the potential role of these breast milk cells for breastfed babies. (12:30 p.m.2 p.m. Tuesday, 4/24, poster in exhibit area)

The buzz about the exquisite little brains of big insects

A long tradition of studying invertebrates to learn about nervous systems has contributed greatly to our understanding of the functional organization, development and evolution of the intricate networks and the neural mechanisms that are at the root of behavior. Insects in particular offer powerful experimental model systems. Today, the most prominent example is the fruit fly, whose genetic and genomic advantages attract many researchers, but whose small size is limiting for some kinds of studies. This session focuses on much larger insects with beautiful and experimentally tractable nervous systems that permit investigations that complement and extend those accomplished with diminutive species. (10:30 a.m. 12:30 p.m. Monday, 4/23, Room 9)

From babies to bandages: reactivation of embryonic processes in adult injury repair

Embryonic tissue development and adult wound repair happen at different points in the life spectrum, but the molecules, cells and processes in that give rise to embryonic development are the same as those activated after injury. Only, the time it takes and the extent of the tissue-forming activities are quite different. Nonetheless, at this session, you might come to find that development and wound repair are just two sides of the same coin. (10:30 a.m. 12:30 p.m. Monday, 4/23, Room 7A)

Could cartilage transplants eliminate the need for bone grafts?

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The Best of Experimental Biology

Posted: April 25, 2012 at 10:13 pm

From breast milk stem cells to bone repair, this years EB conference held a number of exciting advances that could one day be translated into therapies.

Milk stem cells

Australian scientists have found stem cells in breast milk that appear to behave much like embryonic stem cells. The cells differentiated into bone, fat, liver, pancreatic, and brain tissue. Because the cells can be easily collected, researchers hope they may provide a new source of cells for study and possibly future therapies. In addition, the researchers are investigating whether and how these cells are important for the health of breastfed babies.

Spurring bone regrowth

For years, scientists have been searching in vain for therapies that could help bone and cartilage heal and grow. But when researchers from the University of California, San Francisco, tried to regrow cartilage in damaged knees, the tissue instead turned to bone. While the result was unhelpful for their purposes, the researchers realized that cartilage might prove useful in rebuilding damaged bone, and are now exploring such applications.

A study by another group from Tulane University reported that high oxygen levels may help turn on the genetic program that initiates bone regrowth. When tissues samples taken from amputated limbs are exposed to about 20 percent oxygensignificantly more than the 6 percent typically found in the bodythe tissue responds favorably, said Tulanes Mimi Sammarco in a press releasebut only when administered at a certain point in time. The result wont be easily applied to clinical practice because blood vessels constrict after traumatic injury to prevent blood loss, reducing the amount of oxygen that reaches the damaged tissue even more. Thus, more work is needed to understand exactly when during the healing process high oxygen contributes to bone regrowth, and whether the same phenomenon occurs in the intact body.

More oxygen for chronic pain

More oxygen may also help relieve chronic pain. The application of pure oxygen, known as hyperbaric oxygen is used to treat an excruciatingly painful syndrome that divers experience called the bends, which results from the formation of nitrogen gas bubbles in the body as divers return to normal atmospheric pressure at the surface. Although the oxygen helps treat the symptoms, rather than the pain per se, researchers at Washington State University investigated whether the oxygen administration might also help relieve pain. Indeed, treated rats recovered more quickly from experimentally induced chronic pain. The researchers believe that the oxygen is likely to act on the brain to reduce pain, rather than by alleviating inflammation. Studying the mechanism could reveal molecular targets in the brain and possibly stimulate the development of new drugs that act on the same targets, lead author Raymond Quock of WSU said in a press release.

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Biz Beat: Making stem cells "available to the masses"

Posted: April 25, 2012 at 10:13 pm

Mike Ivey writes on all matters money in the spirit of Capital Times founder William T. Evjue, who believed that the concentration of wealth in the U.S. is not healthy for the Democracy.

When UW-Madison's James Thomson in 1998 became the first scientist to grow human embryonic stem cells in a lab, it generated tremendous excitement about the medical possibilities.

Thomson tried to downplay the breakthrough but talk spread about cures for Alzheimers or Parkinsons disease, growing livers for cirrhosis suffers or producing healthy heart cells for cardiac patients.

The miracle cures have been slow in coming, however. Scientists can replicate healthy nerve cells in a Petri dish but havent found a way to replace defective spinal cells in ALS victims, for example.

In many ways, were still at the first steps,Anita Bhattacharyya, a senior scientist in the stem cell program at the UW's Waisman Center, told a business group Tuesday.

Butproducing stem cells for others to use is proving one of Madisons more promising new business ventures. Pharmaceutical companies in particular are using stem cells to test drugs before launching into expensive further testing.

Were making these cells available to the masses, says Chris Parker, chief technology officer at Cellular Dynamics International.

Launched by Thomson -- and backed with $100 million from a local investor group -- Cellular Dynamics International was lauded recently by MIT as one of the 50 most important companies in the world

Since its founding in 2005, the company now counts 107 employees at it offices in University Research Park and is continuing to grow.

Im hiring right now, Parker joked toa lunch crowd of the Wisconsin Technology Council Tuesday.

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Stem cell that may aid healing and repair found in brain

Posted: April 25, 2012 at 10:13 pm

Washington, April 24 : Scientists have discovered a new stem cell in the adult brain and they hope to put the discovery to use to develop methods that can repair diseases and injury to the brain.

These cells can proliferate and form several different cell types - most importantly, they can form new brain cells.

Analysing brain tissue from biopsies, the researchers at the Lund University for the first time found stem cells located around small blood vessels in the brain.

The cell's specific function is still unclear, but its plastic properties suggest great potential. A similar cell type has been identified in several other organs where it can promote regeneration of muscle, bone, cartilage and adipose tissue.

In other organs, researchers have shown clear evidence that these types of cells contribute to repair and wound healing.

Scientists suggested that the curative properties might also apply to the brain. The next step is to try to control and enhance stem cell self-healing properties with the aim of carrying out therapies targeted to a specific area of the brain.

"Our findings show that the cell capacity is much larger than we originally thought, and that these cells are very versatile," said Gesine Paul-Visse, Ph.D., Associate Professor of Neuroscience at Lund University.

"Most interesting is their ability to form neuronal cells, but they can also be developed for other cell types. The results contribute to better understanding of how brain cell plasticity works and opens up new opportunities to exploit these very features," Paul-Visse added.

The study is of interest to a broad spectrum of brain research. Future possible therapeutic targets range from neurodegenerative diseases to stroke.

"We hope that our findings may lead to a new and better understanding of the brain's own repair mechanisms. Ultimately the goal is to strengthen these mechanisms and develop new treatments that can repair the diseased brain," said Dr. Paul-Visse.

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Second U-M Stem Cell Line Now Publicly Available to Help Researchers Find Treatments for Nerve Condition

Posted: April 25, 2012 at 10:13 pm

Newswise ANN ARBOR, Mich. The University of Michigans second human embryonic stem cell line has just been placed on the U.S. National Institutes of Healths registry, making the cells available for federally-funded research. It is the second of the stem cell lines derived at U-M to be placed on the registry.

The line, known as UM11-1PGD, was derived from a cluster of about 30 cells removed from a donated five-day-old embryo roughly the size of the period at the end of this sentence. That embryo was created for reproductive purposes, tested and found to be affected with a genetic disorder, deemed not suitable for implantation, and would therefore have otherwise been discarded when it was donated in 2011.

It carries the gene defect responsible for Charcot-Marie-Tooth disease, a hereditary neurological disorder characterized by a slowly progressive degeneration of the muscles in the foot, lower leg and hand. CMT, as it is known, is one of the most common inherited neurological disorders, affecting one in 2,500 people in the United States. People with CMT usually begin to experience symptoms in adolescence or early adulthood.

The embryo used to create the cell line was never frozen, but rather was transported from another IVF laboratory in the state of Michigan to the U-M in a special container. This may mean that these stem cells will have unique characteristics and utilities in understanding CMT disease progression or screening therapies in comparison to other human embryonic stem cells.

We are proud to provide this cell line to the scientific community, in hopes that it may aid the search for new treatments and even a cure for CMT, says Gary Smith, Ph.D., who derived the line and also is co-director of the U-M Consortium for Stem Cell Therapies, part of the A. Alfred Taubman Medical Research Institute. Once again, the acceptance of these cells to the registry demonstrates our attention to details of proper oversight, consenting, and following of NIH guidelines.

U-M is one of only four institutions including two other universities and one private company to have disease-specific stem cell lines listed in the national registry. U-M has several other disease-specific hESC lines submitted to NIH and awaiting approval, says Smith, who is a professor in the Department of Obstetrics and Gynecology at the University of Michigan Medical School. The first line, a genetically normal one, was accepted to the registry in February.

Stem cell lines that carry genetic traits linked to specific diseases are a model system to investigate what causes these diseases and come up with treatments, says Sue OShea, Ph.D., professor of Cell and Developmental Biology at the U-M Medical School, and co-director of the Consortium for Stem Cell Therapies.

Each line is the culmination of years of preparation and cooperation between U-M and Genesis Genetics, a Michigan-based genetic diagnostic company. This work was made possible by Michigan voters' November 2008 approval of a state constitutional amendment permitting scientists to derive embryonic stem cell lines using surplus embryos from fertility clinics or embryos with genetic abnormalities and not suitable for implantation.

The amendment also made possible an unusual collaboration that has blossomed between the University of Michigan and molecular research scientists at Genesis Genetics, a company that has grown in only eight years to become the leading global provider of pre-implantation genetic diagnosis (PGD) testing. PGD is a testing method used to identify days-old embryos carrying the genetic mutations responsible for serious inherited diseases. During a PGD test, a single cell is removed from an eight-celled embryo. The other seven cells continue to multiply and on the fifth day form a cluster of roughly 100 cells known as a blastocyst.

Genesis Genetics performs nearly 7,500 PGD tests annually. Under the arrangement between the company and U-M, patients with embryos that test positive for a genetic disease now have the option of donating those embryos to U-M if they have decided not to use them for reproductive purposes and the embryos would otherwise be discarded.

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U-M develops new stem cell line as Legislature threatens to cut funding

Posted: April 25, 2012 at 10:13 pm

The University of Michigan may be in the midst of a battle with state GOP lawmakers over its controversial embryonic stem cell research, but that's not stopping the university from strengthening its stem cell research portfolio.

A University of Michigan researcher conducts embryonic stem cell research.

It's also likely to add tension to a battle brewing in Lansing between the Republican lawmakers that decide U-M's budget and university administrators who have declined to tell the Legislature exactly how many human embryos are used during research. Legislators requested that U-M disclose how many embryos it uses more than a year ago but the 50-plus page report university president Mary Sue Coleman turned over to lawmakers in December did not include the exact number of embryos used.

State Rep. Kevin Cotter, R-Mt. Pleasant, a member of the subcommittee that decides how funds are doled out to universities, recently accused U-M of thumbing its nose at the legislature.

Legislators have threatened to withhold up to $7 million in performance funding from U-M if administrators do not fully disclose how many embryos U-M uses.

Coleman says it's unlikely the school will disclose that information.

Mary Sue Coleman

"Even though we were asked specific questions we dont collect the data in this way and we think that focus on these issues, these specific little issues, were trivializing the complexity" of stem cell research, Coleman said recently. "I want to continue to put this in context.... We are doing this according to the strict regulations of the federal government."

Meanwhile, U-M researchers are optimistic their new stem cell line will be instrumental in developing a cure for Charcot-Marie-Tooth disease, a debilitating neurological disorder that causes foot, leg and hand muscles to degenerate early in life.

The new line was derived from a 5-day-old embryo the size of a period. That embryo was created for reproductive purposes, tested and found to be affected with the genetic disorder, deemed not suitable for implantation, and would therefore have otherwise been discarded when it was donated in 2011. According to U-M Charcot-Marie-Tooth disease is one of the most common inherited neurological disorders and affects one in 2,500 people in the United States.

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Embryonic Stem Cells in Court Again

Posted: April 25, 2012 at 10:13 pm

A judicial technicality may decide the fate of NIH-funded human embryonic stem cell research.

By Sabrina Richards | April 24, 2012

Wikimedia Commons, Avjoska

The legality of federally funding human embryonic stem cell (hESC) research is being questioned in court again, and the decision may rest on a technicality, reported ScienceInsider.

National Institutes of Health guidelines released in 2009 lifted the Bush-era restrictions on hESC research, but were met with a lawsuit by adult stem cell researchers that August. A preliminary injunction by the US District Court in Washington, DC, prevented NIH funding for hESCs in August 2010. Just 2 weeks later, the US Court of Appeals for the District Court stayed the injunction, then overturned it for good in April 20113 months before the appeals court dismissed the lawsuit altogether. Now, the case is once again in appeals court, and current arguments focus on whether this earlier decision is binding.

The plaintiffs argue that the 2009 NIH guidelines contravene the 1996 Dickey-Wicker Amendment, which prohibits federal funding for research that may harm or destroy human embryos. NIH argues that the earlier decision should be binding because the plaintiffs are not presenting new arguments, but the plaintiffs counter that the court has yet to rule on whether the NIH guidelines create demand for new hESC lines, which are derived from embryos.

The plaintiffs also argue that comments from opponents of hESC research should have been considered by the NIH when the guidelines were crafted, but the NIH disputes this, saying that the agency was responding to an order from President Obama asking how, not whether, to fund such research.

The Appeals Court may rule within 4 to 6 months, but some observers expect the case to eventually reach the US Supreme Court.

By Jef Akst

Science adviser John Holdren speaks out about how the Obama Administration is handling the controversial research that rendered avian flu transmissible between ferrets.

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Growing up as a neural stem cell: The importance of clinging together and then letting go

Posted: April 25, 2012 at 10:13 pm

Public release date: 25-Apr-2012 [ | E-mail | Share ]

Contact: Kim Irwin kirwin@mednet.ucla.edu 310-206-2805 University of California - Los Angeles Health Sciences

Can one feel too attached? Does one need to let go to mature? Neural stem cells have this problem, too.

As immature cells, neural stem cells must stick together in a protected environment called a niche in order to divide so they can make all of the cells that populate the nervous system. But when it's time to mature, or differentiate, the neural stem cells must stop dividing, detach from their neighbors and migrate to where they are needed to form the circuits necessary for humans to think, feel and interact with the world.

Now, stem cell researchers at UCLA have identified new components of the genetic pathway that controls the adhesive properties and proliferation of neural stem cells and the formation of neurons in early development.

The finding by scientists at the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA could be important because errors in this pathway can lead to a variety of birth defects that affect the structure of the nervous system, as well as more subtle changes that impair cognitive and motor functions associated with disorders such as autism.

The results of the four-year study are published April 26, 2012 in the peer-reviewed journal Neuron.

The UCLA team found that a delicate balance of gene expression enables the pool of neural stem and progenitor cells in early development to initially increase and then quickly stop dividing to form neurons at defined times.

"One of the greatest mysteries in developmental biology is what constitutes the switch between stem cell proliferation and differentiation. In our studies of the formation of motor neurons, the cells that are essential for movement, we were able to uncover what controls the early expansion of neural stem and progenitor cells, and more importantly what stops their proliferation when there are enough precursors built up," said Bennett G. Novitch, an assistant professor of neurobiology, a Broad Stem Cell Research Center scientist and senior author of the study. "If the neurons don't form at the proper time, it could lead to deficits in their numbers and to catastrophic, potentially fatal neurological defects."

During the first trimester of development, the neural stem and progenitor cells form a niche, or safe zone, within the nervous system. The neural stem and precursor cells adhere to each other in a way that allows them to expand their numbers and keep from differentiating. A protein called N-cadherin facilitates this adhesion, Novitch said.

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