Protein tracks calcium levels in MRI

Chemical Engineering professor Arnab Mukherjee has developed a calcium sensor for use in magnetic resonance imaging (MRI) that he hopes can one day track electrical activity in neurons deep in living brains. The tool potentially allows scientists an unprecedented view of brain activity in specific types of cells across the entire brain of a living organism (ACS Sensors 2021, DOI: 10.1021/acssensors.1c01085). “Calcium is the ionic language in which electrical activity in neurons gets converted to biological function,” said Mukherjee, whose study was initiated as a CNSI Challenge Grant. Many groups have developed sensors that detect calcium ions, he says, but most rely on light. That limits their use to the very top few millimeters of the brain that visible or infrared light can penetrate into, and even then, only a small area of the brain can be viewed using a microscope.