Monitoring certain kinds of processes happening inside the brain can be pretty easy or exceedingly difficult. EEG, for example, provides a pretty good look into the brain using relatively simple technology, while measuring light emitted by luminescent proteins within the brain is incredibly challenging.
Now researchers at MIT are adapting MRI technology, coupled with a tiny implant, to be able to measure both electric fields and light at excellent spatial resolution. Previously, the same would require extremely invasive procedures, with wires protruding from the head, that essentially make it impossible to do so in most cases. Accurately measuring electric fields can reveal what the brain is doing, while detecting the presence of fluorescent molecules can be a tool to help discover how to manipulate the brain for therapeutic and scientific purposes.
The researchers relied on a small implantable antenna that is meant to work like the antenna built into the MRI machine. The antenna is designed to pick up radio signals that hydrogen atoms emit in their normal state, and this antenna is well seen under MRI. Nearby electromagnetic fields, emitted by neurons firing, make it so that the antenna’s tuning doesn’t match these signals and the antenna becomes poorly visible when scanned by the MRI.
This phenomenon is so sensitive that neural activity should be detectable, something that the researchers have yet to try in humans, and the same approach is used to detect light.