14 DAY TRIAL // During a recent investigation conducted on unsuspecting lab mice, researchers learned that turning off just two genes in the tiny rodents led to a massive decrease in the amount of physical activity they put forth. The animals' ability to run was the most severely impeded, the team reports.
Given the similarities between the brains of mice and humans, it may be possible that the same connection may also exist in the human brain. Now researchers have a new direction of research for figuring out how to control activity patterns in the brain.
The pair of genes that caused such a significant effort in mice was located inside the muscles themselves. Scientists behind the new work say that this may explain why human couch potatoes find it increasingly difficult to get moving the longer they remain sedentary.
These discoveries may also help explain why so many people have a hard time taking on activities that require physical effort to the smallest degree. In the near future, experts plan to conduct similar genetic investigations on humans as well, so see whether the two genes have the same action in us as well.
Both of them are involved in controlling the actions and activity patterns of a protein called AMP-activated protein kinase (AMPK). Previous researches have determined that this molecule is produced in larger amounts during physical exercises, and that it has multiple paths of action on our cells.
The AMPK complex is made up of several components, of which two are controlled by each of the two genes. The researchers only analyzed how this happened in skeletal muscles, which are muscles over which we can exercise mental control.
What the pair of gene does is it enables the skeletal muscle to convert sugars into energy, which is then used for whatever action is demanded of them. Whenever this mechanism is hindered or interrupted, the muscles lose their ability to function properly, leading to muscle sores, aches and so on.
In the experiments, researchers at the McMaster University, in Canada, manipulate the genomes of young mice in order to shut down the two genes. Even though the animals themselves were in perfect health, the differences between the two study groups became apparent immediately.
“The mice looked identical to their brothers or sisters, but within seconds we knew which ones had the genes and which one didn't,” McMaster expert and study team member Gregory Steinberg explains.
“Mice love to run. While the normal mice could run for miles, those without the genes in their muscle could only run the same distance as down the hall and back. It was remarkable,” the expert adds.
Details of the new investigation were published in the September 5 issue of the esteemed journal Proceedings of the National Academies of Sciences (PNAS), LiveScience reports.