Magnetism controls neurons in brains of mice

IEEE Spectrum : Recently neuroscientists have manipulated the brains of mice using laser light, a technique called optogenetics. However, lasers have limitations, and the technique sometimes requires invasive steps, such as the insertion of fiber-optic cables. Now Ali Guler of the University of Virginia and colleagues have developed a potentially less invasive technique using magnets. It consists of a specially designed gene, dubbed Magneto , that contains two proteins: TRPV₄, which acts as an ion channel gatekeeper, and ferritin, which stores iron. Experimenting with mice, the researchers delivered the gene to the striatum, a part of the brain that processes rewards. When an external magnetic field is applied, the ion channels in the striatum open, mimicking the pleasurable effects of dopamine. The team tested the effectiveness of the technique by confining both Magneto-carrying mice and control mice to a small chamber, half of which was magnetized. The researchers found that the Magneto-carrying mice preferred the magnetized side. Magnets have no effect on normal neurons, Guler says. But if synthetic genes like Magneto could be developed and placed strategically in living organisms, the technique could allow scientists to map neural pathways, manipulate behaviors, and compare neurons in different parts of the brain.