dogmas are there to be shaken. In the research that is practically the job description – even if it is for the parties Involved sometimes just as enjoyable.
a year ago a study in the formation of fresh brain cells in the renowned journal “Nature” appeared, there were not a few scientists from the neurobiology of shock. The paper made the two-decades-old Dogma of the self-renewal of the human brain obsolete. Such a neurogenesis, it is not, beyond the Childhood so the simple conclusion was at the time. So suddenly appeared too hopeless to be replaced by diseases lost cells in adult brains.
However, research drives sometimes roller-coaster, and then it looks now in neuroscience: A neurologist team to María Llorens-Martín of the Universidad Autónoma in Madrid recognizes twelve months after the setback now however, biological innovations in aging brains. As the researchers in the current issue of the scientific journal “Nature Medicine” reports that make adults brains are still hard-working new nerve cells, even into old age, if they are healthy.
however, You have to apply the right methods, in order to make fresh neurons visible. The Team had examined for his study, almost 60 brains of healthy and Alzheimer’s diseased people, and with a new, sophisticated methodology for developing, unfinished neurons wanted.
New nervous cells
In healthy adults, therefore, per square millimeter of thin tissue cross-around 42000-sections of maturing nerve cells detectable. The number of new cells decreased with the age of the brains – in a human at the end of 80 by 30 percent compared to half as old brains.
Nevertheless, a Man still produces new brain cells, such as current work assigned. And what could show the researchers in addition: In the case of Alzheimer’s patients, the neurogenesis is significantly reduced. Even before the appearance of the first symptoms, the regeneration ability of the brain dwindles in comparison to their peers by one-third. It is this finding, which is the least disturbing of unsuccessful Alzheimer’s research could give new impulses.
New nerve cells are created, however, not everywhere in the brain. Find neurologists in an area that is also in other mammals, for the neurogenesis in charge. It is the so-called the dentate Gyrus, a section of the Hippocampus. The Hippocampus plays a Central role in memory formation and is pulled, for example, in Alzheimer’s patients is strongly affected.
Thesis refuted
in 1998, scientists had made in the case of deceased cancer patients in this structure, a crucial and at the same time, happy discovery. The cancer patients had been injected during the treatment before her death as a means of the new, only just by division, the resulting cells will be marked. In the context of the post-mortem examination, the researchers found to their own Surprise, then, unique about the Hippocampus, scattered marks. New nerve cells. Further studies confirmed these results. At least it had for twenty years.
Until a moment ago, in March of last year, Arturo Alvarez-joined Buylla on the Plan. The neuro-scientists from the University of California in San Francisco criticized the previously used detection methods as totally unreliable, and collected with his working group, for five years, brain tissue from operations and of the deceased.
“Ends the debate? I’m not sure. It’s supposed to? In any case,”Heather Cameron, a neuroscientist
Finally he put in place of the old methods, so-called fluorescent antibodies to make in the development of nerve cells visible. While Alvarez-Buylla was able to demonstrate in this way, in the case of a newborn very much active nerve cell growth in the brain, found that he and his colleagues from the child to the age of any newly formed cells in the human brain.
and now again a study appears that the work of the US researcher, contradicts, may seem confusing. However, it is very likely the method critic Alvarez has overlooked-Buylla even some of the crucial things in the methodology. Most importantly, the relevant Preservation techniques for samples of tissue can alter the molecular structure of nerve cells and for a rejuvenation of proof and make them inaccessible.
And there did you have
the authors of The current study this again carefully, and found that the usual formaldehyde solutions for tissue sections after 48 hours of negative effects on the detectability of typical surface molecules of immature nerve cells examined. After six months, these structures can actually be no way to prove it – although the cells are still there.
For many neuro-researchers is likely to bring the observation of the Spaniards great relief. “The work provides clear and definitive proof that neurogenesis persists in old age,” said Paul Frankland, from the canadian Hospital for Sick Children in Toronto, the science magazine “Science”. “For me the thing is placed in order to the files.”
The American Neuroscientist Heather Cameron from the National Institute of health, the United States agrees with her colleague. “It ended the debate? I’m not sure. It’s supposed to? In any case,” she says.
(Tages-Anzeiger)
Created: 29.03.2019, 06:12 PM
