Scientists have developed a method to stimulate small clusters of brain cells using magnetic fields. Using this technique, they were able to control movement in mice.
Understanding how the brain works is an ongoing effort, with a huge number of research teams working intensively to unlock its secrets. As part of this effort, an international group of scientists has developed a new method called magneto-thermal stimulation to activate very small areas of the brain. They hope that the technique could lead to advances in studying and treating neurological disorders and traumatic brain injuries. Direct brain stimulation could also be useful in directly treating conditions such as depression and epilepsy.
The technique involves genetically modifying the targeted neurons using an injected virus so that they produce a specific heat-activated protein. Then, the scientists inject magnetic nanoparticles into the brain regions they want to stimulate. They then introduce a magnetic field, which causes the nanoparticles to heat up and activate the protein in the targeted neurons, causing them to fire.
“Using our method, we can target a very small group of cells, an area about 100 micrometers across, which is about the width of a human hair,” says Arnd Pralle, a professor of physics in the University at Buffalo College of Arts and Sciences, who was involved in the study.
The researchers were able to activate neurons in the brain’s motor cortex in mice, causing the animals to run. Stimulating neurons in another region called the striatum caused the mice to turn around. Finally, when the team activated a deeper region of the brain, the mice were frozen on the spot, as they were unable to move their limbs.