Neural stem cells shown in green, neurons in red. (Credit: Image courtesy of University of California - Irvine)
Posted on 11/03/2007 2:32:43 PM PDT by neverdem
ScienceDaily (Nov. 2, 2007) — New UC Irvine research is among the first to demonstrate that neural stem cells may help to restore memory after brain damage.
In the study, mice with brain injuries experienced enhanced memory -- similar to the level found in healthy mice -- up to three months after receiving a stem cell treatment. Scientists believe the stem cells secreted proteins called neurotrophins that protected vulnerable cells from death and rescued memory. This creates hope that a drug to boost production of these proteins could be developed to restore the ability to remember in patients with neuronal loss.
"Our research provides clear evidence that stem cells can reverse memory loss," said Frank LaFerla, professor of neurobiology and behavior at UCI. "This gives us hope that stem cells someday could help restore brain function in humans suffering from a wide range of diseases and injuries that impair memory formation."
LaFerla, Mathew Blurton-Jones and Tritia Yamasaki performed their experiments using a new type of genetically engineered mouse that develops brain lesions in areas designated by the scientists. For this study, they destroyed cells in the hippocampus, an area of the brain vital to memory formation and where neurons often die.
To test memory, the researchers gave place and object recognition tests to healthy mice and mice with brain injuries. Memories of place depend upon the hippocampus, and memories of objects depend more upon the cortex. In the place test, healthy mice remembered their surroundings about 70 percent of the time, but mice with brain injuries remembered it just 40 percent of the time. In the object test, healthy mice remembered objects about 80 percent of the time, while injured mice remembered as poorly as about 65 percent of the time.
The scientists then set out to learn whether neural stem cells from a mouse could improve memory in mice with brain injuries. To test this, they injected each mouse with about 200,000 neural stem cells that were engineered to appear green under ultraviolet light. The color allows the scientists to track the stem cells inside the mouse brain after transplantation.
Three months after implanting the stem cells, the mice were tested on place recognition. The researchers found that mice with brain injuries that also received stem cells remembered their surroundings about 70 percent of the time -- the same level as healthy mice. In contrast, control mice that didn't receive stem cells still had memory impairments.
Next, the scientists took a closer look at how the green-colored stem cells behaved in the mouse brain. They found that only about 4 percent of them turned into neurons, indicating the stem cells were not improving memory simply by replacing the dead brain cells. In the healthy mice, the stem cells migrated throughout the brain, but in the mice with neuronal loss, the cells congregated in the hippocampus, the area of the injury. Interestingly, mice that had been treated with stem cells had more neurons four months after the transplantation than mice that had not been treated.
"We know that very few of the cells are becoming neurons, so we think that the stem cells are instead enhancing the local brain microenvironment," Blurton-Jones said. "We have evidence suggesting that the stem cells provide support to vulnerable and injured neurons, keeping them alive and functional by making beneficial proteins called neurotrophins."
If supplemental neurotrophins are in fact at the root of memory enhancement, scientists could try to create a drug that enhances the release or production of these proteins. Scientists then could spend less time coaxing stem cells to turn into other types of cells, at least as it relates to memory research.
"Much of the focus in stem cell research has been how to turn them into different types of cells such as neurons, but maybe that is not always necessary," Yamasaki said. "In this case, we did not have to make neurons to improve memory."
The results of the study appear Oct. 31 in the Journal of Neuroscience.
UCI scientists Debbi Morrissette, Masashi Kitazawa and Salvatore Oddo also worked on this study, which was funded by the National Institute on Aging, the National Institutes of Health, and a California Institute for Regenerative Medicine postdoctoral scholar award.
Adapted from materials provided by University of California - Irvine.
Stem Cells Spark Murine Memory Recovery link to another review
I emailed the who author who provided the addy asking what was the source of the stem cells, and if they were embryonic, were immunosuppressive drugs used. I’ll let you know if I get a reply.
IT certainly didn't work on Cynthia McKinney.
Oh wait... She was born impaired.
I used the search function for Journal of Neuroscience.
“Embryonic Stem Cells” did deliver about 18 titles.
If ESCs were used in the study...it’s suprising that would not be
in the title of the present work.
Seeing how there are plenty of researchers hoping to “go for the gold”
(a Nobel Prize) by getting the first workable ESC-based cure/therapy
(but once you hear from the authors, I may have to eat “crow”
on that point! With lots of BBQ sauce, please.)
The mouse models are monoclonic anyway, so immunosuppressive drugs are not generally required for transplantation. This fact makes “things that work in mice” appear to be far more useful than they ever will be in humans.
I dug up the methods and materials for a stem cell study in Science, IIRC, which I posted within the last year. Cyclosporine was the immunosupressant, IIRC.
Bump
It's the last link in comment# 1. Thanks for the tip about monoclonic mouse models.
Final TB count: 212 test positive at 1 chicken plant
Revolutionary Laser Technique Destroys Viruses And Bacteria Without Damaging Human Cells (AZ)
FReepmail me if you want on or off my health and science ping list.
I think neural stem cells are adult stem cells. Embryonic stem cells are undefined, and can become any type.
“Will I be able to play the violin after these treatments?”
“Yes, absolutely.”
“Great! I never could play violin before.”
Neuroscientists will have to figure out how to replace just about the entire brain before they can help vicious demented Demagogues like Cynthia.....
Where does a fetus get its neural stem cells, except from the original embryo that developed from the fertilized egg?
It will never happen. See?
There is liberal natural rejection of the human brain.
They are more like this piece of evolution.
LOL!
By the time there is a fetus, there are no more embryonic stem cells. Embryonic stem cells are harvested during a small window of time. (about four days after the embryo is created) After that point, the stem cells become dedicated to a specific purpose, and are no longer embryonic.
Fetuses, Children, and Adults all have the same kind of stem cells. They are defined for one specific purpose. The reason embryonic stem cells are considered (by some) to be more valuable is because they are not defined to a specific purpose. Therefore they can theoretically become any kind that they need to be. Neural stem cells from a fetus and from an adult would be the same, and limited to neural functions.
From what cells are the organism's future gametes, i.e. germ cells, spermatozoa or oocytes, derived?
Metazoan gametes come from germ cells. After differentiation and further maturation, they will become sperm or egg capable of fertilization.
I am not sure what you are after here, but you have maxed out my biology knowledge. Maybe you could explain to me your purpose? If I am incorrect about the information I am stating, just tell me. I am always willing to learn.
I wonder how far removed from totipotency are germ cells from the original fertilized egg. Are they copies of the first mitosis? That's my suspicion. Do you have any good links? All of my biology books are dated.
Human cells have this capacity only during the first few divisions of a fertilized egg. After 3 - 4 divisions of totipotent cells, these cells will not be able to differentiate into any cell type.
I don’t know much about these. I found this link, which was helpful.
http://www.umdnj.edu/gsbsnweb/stemcell/scofthemonth/2007/germstemcelllay.htm
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