Figure 5. . Concept illustration.

Schematic illustration of the novel concept to use MENs for ‘mapping’ the brain for noninvasive electric field stimulation of selected regions deep in the brain. (A) MENs are forced into the brain across blood–brain barrier via application of a d.c. magnetic field gradient. (B) When in the brain, MENs are being distributed over the entire brain or in selected regions via application of spatially varying d.c. magnetic field gradients. The presence of MENs effectively creates a ‘new brain microenvironment’, in which the intrinsic electric signals due to the neural activity are strongly coupled at the subneuronal level to the external magnetic fields generated by remote sources. (C) Such coupling can be used for noninvasive high-efficacy stimulation of selected regions deep in the brain via application of focused and relatively low (˜100 Oe) near-d.c. (˜<1000 Hz) magnetic field.

MEN: Magnetoelectric nanoparticle.