In Brief
Researchers have established a new method of controlling the movements of mice in an attempt to better understand the workings of the brain. Genetic engineered mouse brains respond to temperature and electric current with the flick of a switch. This research could help people with mental health issues.

Simon Says

A team of researchers at the University of Buffalo has used magneto-thermal stimulation to control the movements of mice.

These results were achieved working with mice that had been genetically engineered such that targeted neurons would produce ion channels sensitive and even receptive to temperature. Nanoparticles consisting of a cobalt-ferrite core coated in manganese ferrite were injected into the brain, attaching themselves to neurons.

Applying an alternating magnetosphere causes the magnetization of these nanoparticles to switch back and forth, raising their temperature. As a result, the ion channels open up, causing the associated neurons to fire.

neurology magneto-thermal stimulation brain mice
Neural cells in a mouse’s striatus. By stimulating cells in the motor cortex, the striatum, and a deep section of the brain, respectively, the mice could be compelled to start running, turn around, and come to a halt. Image credit: Munshi et al., eLife

Inside the Mind

This research isn’t really about bossing mice around — it’s about linking specific parts of the brain to the movements and behaviors they control. Understanding how the brain works in this respect could help develop treatments for conditions that affect particular groups of neurons, including Parkinson’s disease, dystonia, and traumatic brain injuries.

“There is a lot of work being done now to map the neuronal circuits that control behavior and emotions,” said Professor of Physics Arnd Pralle, the lead researcher. “The technique we have developed could aid this effort greatly.”

Techniques like transcranial magnetic stimulation already allow us to tinker with the brain, and research has shown that Optogenetics can be used to make major changes to the behavior of mice in a lab setting. However, magneto-thermal stimulation is considered less invasive than these other methods. No evidence of brain damage was found in the mice used during testing.

The researchers hope to expand their studies by figuring out how to stimulate multiple parts of the brain at the same time.