You are here
Do Viruses Make Us Smarter?
A new study from Lund University in Sweden indicates that inherited viruses that are millions of years old play an important role in building up the complex networks that characterize the human brain. The findings were published in Cell Reports.
Researchers have long been aware that endogenous retroviruses constitute approximately 5% of human DNA. For many years, these viruses were considered junk DNA of no real use, a side effect of our evolutionary journey.
In the new study, Dr. Johan Jakobsson and his colleagues show that retroviruses seem to play a central role in the basic functions of the brain –– specifically, in the regulation of which genes are to be expressed and when. The findings indicate that, over the course of evolution, the viruses took an increasingly firm hold on the “steering wheel” in our cellular machinery. The reason the viruses are activated specifically in the brain is probably due to the fact that tumors cannot form in nerve cells, unlike in other tissues, the authors say.
“We have been able to observe that these viruses are activated specifically in the brain cells and have an important regulatory role,” Kakobsson explained. “We believe that the role of retroviruses can contribute to explaining why brain cells in particular are so dynamic and multifaceted in their function. It may also be the case that the viruses’ more or less complex functions in various species can help us to understand why we are so different.”
The article, based on studies of neural stem cells, shows that these cells use a particular molecular mechanism to control the activation processes of the retroviruses. The discovery provides scientists with an insight into the innermost workings of the most basic functions of nerve cells. At the same time, the results open up potential for new research paths concerning brain diseases linked to genetic factors.
“I believe that this can lead to new, exciting studies on the diseases of the brain,” Jakobsson said. “Currently, when we look for genetic factors linked to various diseases, we usually look for the genes we are familiar with, which make up a mere 2% of the genome. Now we are opening up the possibility of looking at a much larger part of the genetic material, which was previously considered unimportant. The image of the brain becomes more complex, but the area in which to search for errors linked to diseases with a genetic component, such as neurodegenerative diseases, psychiatric illness, and brain tumors, also increases.”
Sources: Lund University; January 12, 2015; and Cell Reports; December 24, 2014.