Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The reason for mammals' ageing lies in the brain

21.05.2007
To date, there are two basic concepts of reasons for ageing. The first one is death as a result of damage accumulation, and the second is death as a suicide program. There are multiple arguments in favour of both concepts.

A new – astrocytic – hypothesis has been put forward by Aleksei Boyko, Ukrainian researcher, specialist of the National Agrarian University of Ukraine. In the framework of this hypothesis, ageing is treated as a result of changes in cerebrum cells. The key role is played by transmutation of cells of the radial neuroglia into stellate cells - astrocytes. Since such cell transmutation is a programmed process, the researcher is inclined to the opinion that ageing and following death have been programmed.

The researcher analyzed and compared animals with different ageing rates, and noticed that the majority of reptile, fish and amphibian species which grow old rather slowly have a very high regenerative activity of neural tissue. In other words, these species are able to quickly eliminate nervous system damage and replace extinct nerve cells (neurons). Mammals and birds have almost fully lost the regenerative capacity of the neural tissue, with new neurons formed only in certain parts of the cerebrum, for example, in the walls of the lateral ventricles of the hippocampus. Neuron predecessors – neuroblasts – migrate into various parts of the brain via radial neuroglia fibres, and turn into full-fledged neurons to replace extinct or damaged cells.

The researchers have found out that the mammals undergo changes during their life, with gradual transformation of radial neuroglia cells and transmutation into astrocytes. The astrocytes do not allow neuron predecessors to migrate to the required areas. Thus, renovation of brain cells becomes impossible, and brain cells, having lost their vital resource, ultimately mortify. Such age-specific brain changes undoubtedly cause changes to other internal and organ systems of the organism, with vascular derangements, hormonal status change, brygmus, alopecia, intercellular collagen accumulation, among the common signs of ageing. In contrast to mammals, amphibians such as fish and reptiles preserve their radial neuroglia cells throughout the life cycle, and ageing happens more slowly.

... more about:
»Neuroglia »Neuron »ageing »astrocyte

According to the researchers' astrocyte hypothesis, this is a probable ageing mechanism. They believe that it is the presence or absence of radial neuroglia cells that determines the life span.

Nadezda Markina | alfa
Further information:
http://www.informnauka.ru

Further reports about: Neuroglia Neuron ageing astrocyte

More articles from Life Sciences:

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>