Scientists use magnetic fields to remotely stimulate brain — and control body movements

Scientists have used magnetic nanoparticles to stimulate neurons deep in the brain to evoke body movements of mice. This image shows a section of a mouse brain with injected magnetic nanoparticles (colored red) covering targeted cells in the striatum. Credit: Munshi et al, eLife

The minimally invasive technique could lead to advances in mapping the brain and treating neurological disease

A transmitted light image shows the striatum, a region of the mouse brain involved in motor activity planning. The image is overlaid with a colored visualization highlighting cells (in green) that are targeted for neurostimulation. These cells have been infected with a virus that causes them to produce temperature-sensitive ion channels, which can be stimulated remotely via magnetic nanoparticle heating. Credit: Munshi et al, eLife

BUFFALO, N.Y. — Scientists have used magnetism to activate tiny groups of cells in the brain, inducing bodily movements that include running, rotating and losing control of the extremities — an achievement that could lead to advances in studying and treating neurological disease.

The technique researchers developed is called magneto-thermal stimulation. It gives neuroscientists a powerful new tool: a remote, minimally invasive way to trigger activity deep inside the brain, turning specific cells on and off to study how these changes affect physiology.

“There is a lot of work being done now to map the neuronal circuits that control behavior and emotions,” says lead researcher Arnd Pralle, PhD, an associate professor of physics in the University at Buffalo College of Arts and Sciences. “How is the computer of our mind working? The technique we have developed could aid this effort greatly.”

Understanding how the brain works — how different parts of the organ communicate with one another and control behavior — is key to developing therapies for diseases that involve the injury or malfunction of specific sets of neurons. Traumatic brain injuries, Parkinson's disease, dystonia and peripheral paralysis all fall into this category.

The advances reported by Pralle’s team could also aid scientists seeking to treat ailments such as depression and epilepsy directly through brain stimulation.

The study, which was done on mice, was published Aug. 15 in eLife, an open-access, peer-review journal. Pralle’s team included first authors Rahul Munshi, a UB PhD candidate in physics, and Shahnaz Qadri, PhD, a UB postdoctoral researcher, along with researchers from UB, Philipps University of Marburg in Germany and the Universidad de Santiago de Compostela in Spain.

Magneto-thermal stimulation involves using magnetic nanoparticles to stimulate neurons outfitted with temperature-sensitive ion channels. The brain cells fire when the nanoparticles are heated by an external magnetic field, causing the channels to open.