The neuroscientists and doctors who are pioneers in the new medical field of brain hacking (no, that’s not an official term) would like to have precise control over the 86 billion neurons in the human brain. All those neurons turn on and off in complex patterns to manage the body and behavior. The brain hackers would like to treat the brain like a control panel, flipping certain patches of neurons on or off to help with disorders like epilepsy and depression.

But activating specific neurons isn’t exactly easy. The typical technique for neural stimulation uses implanted metal electrodes that send current through surrounding brain cells, but these activate relatively broad swaths of neurons, and scar tissue that gradually forms around the metal can block the flow of current. A new technique called optogenetics enables researchers to control individual cells with flashes of light, but that requires somehow getting a light into the brain.

A tiny “microcoil” that could be inserted into the brain offers a new way. Running a current through the insulated coil generates magnetic fields that activate neurons through electromagnetic induction,…[Read more]