Sakhrat Khizroev of Florida International University in Miami and his team inserted 20 billion of these nanoparticles into the brains of mice. They then switched on a magnetic field, aiming it at the clump of nanoparticles to induce an electric field. An electroencephalogram showed that the region surrounded by nanoparticles lit up, stimulated by this electric field that had been generated.
Khizroev’s goal is to build a system that can both image brain activity and precisely target medical treatments at the same time. Since the nanoparticles respond differently to different frequencies of magnetic field, they can be tuned to release drugs.
Although beyond the scope of current research, Khizroev’s nanoparticle system may offer a new way to interact with computers. He hasn’t tried it yet, but he says running it in reverse, so that the nanoparticles produce a measurable magnetic field in response to the brain’s own electrical fields, is possible. Our brain states would then become input parameters for computers, which would be able to directly stimulate specific regions of the brain in return.
An 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.
Materials and methods: Approximately 10 µg 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.