Researchers Have Used Magnetic Fields To Control Brain Cells In Mice
Scientists were able to activate brain cells in mice using magnetic fields and in turn make them spin, run and freeze in place. Through these experiments scientists could be able to determine which brain circuits control which behavior in animals, and then this would allow them to better understand similar pathways in the human brain. The ultimate goal of this research is to help scientists understand how these lab mice encode more complex behaviors and emotions.
Using implanted electrodes, scientists were also able to control the thoughts and movements of monkeys during one experiment, and in another they were able to genetically engineer brain circuits that could be turned on using a beam of laser. Furthermore, in a 2014 experiment, researchers were able to allow one monkey to control another using brain implants. The only problem with these experiments is the process through which the brain is accessed, because it includes either implanting electrodes or a bulky cable. Both of these methods can cause brain damage and the subjects are unable to move away from the connecting cables.
To address this issue, scientists have the transcranial magnetic stimulation method, which is an FDA-approved treatment for depression that is resistant to medication. One of the main objectives of this new study using the mice was to target specific brain cells, instead of wide areas of the brain. In order to do this, the research team injected small magnetic nanoparticles that attach themselves to brain cells and which are then activated by the magnetic field. As the magnetic field interacts with the nanoparticles, they heat up along with the cells. This then opens up temperature-sensitive channels in the brain flooding them with positive ions and causing them to activate. This technique allowed scientists to control the movements of the mice to a great degree, including being able to make them run, turn, lose control of their extremities and freeze in place.
Besides the enhanced mobility and less invasive access to the brain, this method also has the advantage of operating multiple regions of the brain at the same, due to the wide area of influence of the magnetic field. This is very advantageous in primates where multiple regions of the brain need to be activated to perform certain tasks.
However, this technique is not intended for use in human brains, because it makes use of nanoparticles and genetic engineering. The main purpose of these experiments is to understand which regions of various animals’ brains are responsible for various movements and tasks.The results of this research could be used to understand which brain circuits can be used to treat Parkinson’s disease in humans for example. The idea is that even though the method itself might not be the right one for use in humans, laying out the theoretical framework for various brain functions might be very useful later on when new methods are discovered.