DEC 06, 2020 5:11 AM PST

Free Radicals May Actually be Good for the Brain

WRITTEN BY: Carmen Leitch

Reactive oxygen species (ROS) are a type of highly reactive molecule, because they have a lone electron in their outer shell. These so-called free radicals want to donate or steal single electrons from other molecules. Studies have shown that free radicals can be destructive.

A mouse hippocampal neuron studded with thousands of synaptic connections (yellow).  / Credit: Image by Lisa Boulanger / Princeton University

Work in mouse models has suggested, however, that free radicals are also involved in the regulation of cellular processes in the brain, and they are important for the brain's adaptability. Reporting in Cell Stem Cell, scientists have focused on a region of the brain that is critical to learning and memory, called the hippocampus, to learn more about the effect of free radicals.

The scientists linked the creation of new neurons, and their specification, to ROS levels. Lower levels of ROS were connected to an increase in the proliferation and differentiation of neurons, even in adult animals.

"This so-called adult neurogenesis helps the brain to adapt and change throughout life. It happens not only in mice, but also in humans," said Professor Gerd Kempermann, speaker of the German Center for Neurodegenerative Diseases (DZNE) at Dresden site and research group leader at the Center for Regenerative Therapies Dresden (CRTD).

New nerve cells form from stem cells that are sometimes called neural precursors. "These precursor cells are an important basis for neuroplasticity, which is [what] we call the brain's ability to adapt," said Kempermann.

Neural stem cells in mice were found to have high levels of free radicals compared to differentiated nerve cells.

"This is especially true when the stem cells are in a dormant state, which means that they do not divide and do not develop into nerve cells," said Kempermann. As the levels of free radicals increases, the stem cells are encouraged to divide. "The oxygen molecules act like a switch that sets neurogenesis in motion."

While normal cellular metabolism generates waste products including free radicals, they are usually disposed of and are not allowed to accumulate in the cell. If they do, damage called oxidative stress can occur.

"Too much of oxidative stress is known to be unfavorable. It can cause nerve damage and trigger aging processes," explained Kempermann. "But obviously this is only one aspect and there is also a good side to free radicals. There are indications of this in other contexts. However, what is new and surprising is the fact that the stem cells in our brains not only tolerate such extremely high levels of radicals, but also use them for their function."

Antioxidants can help counteract the effects of radicals and stop oxidative stress. Many fruits and vegetables contain antioxidants.

"The positive effect of antioxidants has been proven and is not questioned by our study. We should also be careful with drawing conclusions for humans based on purely laboratory studies," cautioned Kempermann. "And yet our results at least suggest that free radicals are not fundamentally bad for the brain. In fact, they are most likely important for the brain to remain adaptable throughout life and to age in a healthy way."

Sources: AAAS/Eurekalert! via DZNE - German Center for Neurodegenerative Diseases, Cell Stem Cell

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
NOV 27, 2020
Cell & Molecular Biology
UVC Rays May be a Bigger Cancer Risk Than Known
NOV 27, 2020
UVC Rays May be a Bigger Cancer Risk Than Known
The sun emits different kinds of light and rays including visible and ultraviolet (UV) and infrared. Some of those forms ...
DEC 03, 2020
Cell & Molecular Biology
7 Considerations When Purchasing a Microvolume UV-Vis Spectrophotometer
DEC 03, 2020
7 Considerations When Purchasing a Microvolume UV-Vis Spectrophotometer
It all started with the Thermo Scientific™ NanoDrop™ 1000 as the first microvolume UV-Vis spectrophotometer, ...
DEC 03, 2020
Space & Astronomy
Health Issues from Spaceflight Caused by Mitochondria
DEC 03, 2020
Health Issues from Spaceflight Caused by Mitochondria
Spending an extended time in space is known to impact various aspects of health, from muscle and bone regeneration to th ...
DEC 11, 2020
Microbiology
When Microbes Battle for Survival, the Weakest Can Win
DEC 11, 2020
When Microbes Battle for Survival, the Weakest Can Win
Our world is filled with different types of bacteria, and they have to coexist with one another. They have to compete fo ...
DEC 28, 2020
Cancer
Revealing a Critical Protein Involved in the Pentose Phosphate Pathway in Cancer
DEC 28, 2020
Revealing a Critical Protein Involved in the Pentose Phosphate Pathway in Cancer
The metabolism of cancer has interested scientists in recent decades. Many cancers conduct "normal" metabolism ...
JAN 17, 2021
Genetics & Genomics
New Insights Into Kabuki Syndrome
JAN 17, 2021
New Insights Into Kabuki Syndrome
Kabuki syndrome is a rare multisystemic disorder that causes delays in growth, distinctive facial features, short statur ...
Loading Comments...