The meshes—about the length of a pen cap—are able to do something unprecedented: once injected into the brain of a living mouse, they can safely stimulate individual neurons and measure the cells’ behavior for more than a year.
Electronic brain interfaces like these could someday be crucial for people with neurological diseases such as Parkinson’s. The disease causes a group of neurons in one area of the brain to begin dying off, triggering uncontrollable tremors and shakes. Sending targeted electrical jolts to this area can help whip the living neurons back into shape and stop Parkinson’s symptoms.
The extremely flexible mesh, made of gold wires sandwiched between layers of a polymer, easily coils into a needle so it can be injected rather than implanted, avoiding a more extensive surgery. Part of the mesh sticks out though the brain and a hole in the skull so that it can be wired up to a computer that controls the electric jolts and measures the neurons’ activity. But eventually, Lieber says, the controls and power supply could be implanted in the body, as they are in today’s systems for deep brain stimulation.
The researchers foresee the mesh having many uses beyond Parkinson’s. It might help treat depression and schizophrenia more precisely than today’s drugs, which bathe the entire brain in chemicals and cause an array of side effects.
First, though, it needs to be tested in humans. Lieber’s group is partnering with doctors at Massachusetts General Hospital and will soon begin experiments in people with epilepsy
The device is flexible enough to be injected by a needle. The net-like structure prevents it from disrupting neurons too much once implanted.