This process is said to mimic some of the effects of exercise, with the team hopeful the technique can be used to stimulate muscle recovery for aging and diseased subjects.
The researchers started out looking to explore the possibility that weak magnetism can naturally interact with our muscles, so began their experiments by cancelling out the effects of all environmental magnetic fields and observing the effects on muscle cells. The scientists did indeed find that these cells grew more slowly in the absence of any surrounding magnetic fields.
The team then shifted its focus to a protein called TRPC1, investigating its role in muscle growth by deleting it from a set of genetically engineered muscle cells. These cells proved unresponsive to any magnetic field, until the scientists reinserted the protein in small vesicles, making the cells magnetically sensitive once again.
The magnetic fields used in the experiments were only 10 to 15 times stronger than Earth's magnetic field, but a lot weaker than a typical bar magnet. This suggests that this type of weak magnetism could be a sweet spot for promoting good muscle health, with the protein TRPC1 acting as an antenna. The experiments also "strongly support the notion" that Earth's magnetic field drives biological responses by interacting with muscle cells, according to the team.