Magnetoelectric 'spin' on stimulating the brain

Aim: The in vivo study on imprinting control region mice aims to show that magnetoelectric nanoparticles may directly couple the intrinsic neural activity-induced electric fields with external magnetic fields. Methods: Approximately 10 mu g of CoFe2O4-BaTiO3 30-nm nanoparticles have been intravenously administrated through a tail vein and forced to cross the blood-brain barrier via a d.c. field gradient of 3000 Oe/cm. A surgically attached two-channel electroencephalography headmount has directly measured the modulation of intrinsic electric waveforms by an external a.c. 100-Oe magnetic field in a frequency range of 0-20 Hz. Results: The modulated signal has reached the strength comparable to that due the regular neural activity. Conclusion: The study opens a pathway to use multifunctional nanoparticles to control intrinsic fields deep in the brain.