How to control the brain from a distance

Kirill Stasevich, "Science and Life"

When we see someone controlling someone else's brain from a distance, forcing someone else to run, jump, wave his hands, etc. against his will, it means that we are watching a science fiction movie, or some kind of mystical fantasy. Although modern science is doing everything possible to make such fiction come true. 

Researchers from The University of the State of New York in Buffalo has learned to literally control a mouse - using the method of magnetic temperature stimulation. It was not without genetic engineering: the animals were embedded with a protein gene that controls the flow of ions through the cell membrane and which simultaneously reacts to temperature. 

Such an ion channel, once in the membrane of nerve cells, stimulated their activity when heated: the ion gates opened, the ions regrouped, the potential difference between outside and inside the membrane changed, and the cell generated an electrochemical pulse.

Magnetic nanoparticles made of cobalt ferrite and manganese ferrite worked as a heater. Nanoparticles were injected into a certain area of the brain where there were genetically modified neurons; the particles stuck to the surface of the cells, and now it only remained to warm them up in an alternating magnetic field – due to rapid changes in magnetization, the nanoparticles released heat, activating thermosensitive ion channels. 

This method was developed by Arnd Pralle and his colleagues for about ten years – it all started with the stimulation of cell colonies growing in laboratory dishes, they were replaced by roundworms, and now it has come to mice. 

In an article in eLife, researchers write that they experimented with the motor areas of the brain: so, acting on the motor cortex, mice were forced to run, and when the striped body was stimulated, rodents began to spin on the spot. Stimulation of other zones plunged the mice into a stupor, so that they could not move a single paw. According to the authors of the work, the neurons that were affected by nanoparticles and the field remained alive and healthy, despite repeated stimulation. 

The advantage of magnetic temperature stimulation is that it can be used to include very small neural groups, only 100 micrometers across. (By the way, we described a similar method two years ago, when researchers from the Massachusetts Institute of Technology published an article about brain stimulation with warm nanoparticles.) 

Of course, some readers may recall that optogenetics allows us to do something similar, when we first supply a neuron with a light-sensitive protein using the same genetic engineering, and then activate it with a light pulse. But to send a light pulse to the brain, you need a special fiber-optic cable that will illuminate the necessary neurons in the brain. With magnetic temperature stimulation, no cables are needed, an external magnetic field acts without wires, and nothing sticks out of the head. 

It is worth adding that now neuroscientists widely use the method of transcranial magnetic stimulation, when a powerful magnetic field directed from the outside increases or decreases the activity of some parts of the brain. 

But in this case, we are not talking about groups of neurons with diameters of 100 microns, but about sufficiently large areas of nervous tissue – although even such a wide impact gives very impressive results: for example, a few years ago, specialists from Northwestern University with the help of transcranial magnetic stimulation managed to improve the memory of several people. 

Portal "Eternal youth" http://vechnayamolodost.ru  30.08.2017