Attractive living conditions keep the “hippocampus” – the control center of memory located in the brain – young to a certain extent. The reason for this are molecular mechanisms that affect gene control. These current findings from studies in mice provide clues as to why an active, varied life can help maintain mental fitness in old age. Researchers from the DZNE and the Center for Regenerative Therapies Dresden (CRTD) at the TU Dresden report on this in the journal “Nature Communications”.
Human DNA – and this also applies to mice – contains thousands of genes. Decisive for the function of a cell and whether it is healthy or not, however, is not only the genetic blueprint, but above all which genes can be switched on or off at all. Aging, living conditions and behavior are known to influence this ability to activate genes. The phenomenon – called “epigenetics” – was the focus of the current study. Researchers around Dr. Sara Zocher and Prof. Gerd Kempermann examined mice that had grown up in different environments. A group of animals experienced a “charming” environment with toys and tunnels from their youth. Such employment opportunities were not available to the mice in a second group.
Attachments to the DNA
When examining the genetic make-up, the scientists found that in those mice that grew up in the attractive environment, certain chemical markings on the DNA changed only relatively little with age. In mice from the low-irritation environment, these changes were much more pronounced – in comparison between young and older animals. “We have recorded so-called methyl groups that stick to the DNA, so to speak,” explains Gerd Kempermann, spokesman for the DZNE site in Dresden, DZNE research group leader and scientist at the CRTD. “These chemical attachments do not change the genetic information itself. Rather, they influence whether individual genes can be activated or not.”
Plastic brains
Such “epigenetic markings” tend to decrease with age, but the decrease in methyl groups was comparatively small in animals with stimulating living conditions. In old mice from a varied environment, the gene activity remained so to a certain extent young. This particularly affected a number of genes that are important for the formation of new nerve cells and cellular connections in the hippocampus. “From an epigenetic perspective, these animals retained a younger hippocampus,” says Kempermann. The brains of these mice were therefore more malleable – experts speak of greater “neuroplasticity” – than those of their peers who had developed in an environment with little irritation.
No behavioral experiments were carried out in the course of the current study. From many other studies, however, we know that mice that grew up in a stimulating environment perform better in memory tests than those from a low-stimulus environment, says Kempermann. “It seems likely that this mental fitness can be traced back to the stabilization of the methylation pattern, which we have now established,” says the neuroscientist. “The question, of course, is to what extent our observations also apply to people. The situation is probably more complicated here. It’s about how living conditions influence behavior and a person’s reaction to external stimuli is far more complex than that of mice. But we have good reasons to assume that the basic epigenetic principles in humans are the same as in mice. “
Originalveröffentlichung
Environmental enrichment preserves a young DNA methylation landscape in the aged mouse hippocampus, Zocher et al., Nature Communications (Juni 2021)
DOI: 10.1038/s41467-021-23993-1
URL: https://doi.org/10.1038/s41467-021-23993-1 & https://rdcu.be/cm3nD
About the German Center for Neurodegenerative Diseases (DZNE)
The DZNE is a research facility that deals with all aspects of neurodegenerative diseases (such as Alzheimer’s, Parkinson’s and ALS) in order to develop new approaches in prevention, therapy and patient care. With its ten locations, it bundles nationwide expertise within a research organization. The DZNE cooperates closely with universities, university clinics and other institutions at home and abroad. It is publicly funded and is a member of the Helmholtz Association.
Web: www.dzne.de
About the Center for Regenerative Therapies Dresden (CRTD)
At the Center for Regenerative Therapies Dresden (CRTD) of the TU Dresden, top researchers from more than 30 countries dedicate themselves to new therapeutic approaches. They decipher the principles of cell and tissue regeneration and explore their use for the diagnosis, treatment and healing of diseases. The CRTD links laboratory and clinic, connects scientists with doctors, uses specialist knowledge in stem cell research, developmental biology, genome editing and tissue regeneration to ultimately heal diseases such as Alzheimer’s and Parkinson’s, hematological diseases such as leukemia, metabolic diseases such as diabetes and eyes – and to achieve bone diseases.
Since 2016, the CRTD has been one of three institutes of the central scientific facility Center for Molecular and Cellular Bioengineering (CMCB) at TU Dresden. CMCB makes a decisive contribution to the profile of the TU Dresden in the field of health sciences, biomedicine and bioengineering.
Web: www.tu-dresden.de/cmcb/crtd
Web: www.tu-dresden.de/cmcb
Information for journalists:
Dr. Magdalena Gonciarz
Technical University Dresden
Center for Molecular and Cellular Bioengineering (CMCB)
[email protected]
Dr. Marcus Neitzert
DZNE, communication department
Tel.: 0228 43302267
E-mail: [email protected]
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