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.