Functional MRI (fMRI) imaging has provided an amazing look into the activities happening inside the brain. Specifically, it allows scientists to study intra cerebral blood flow under the scalp, which is indicative of the goings-on of neurons in the vicinity of the flowing blood. Therefore this is an indirect measurement, which is a pretty crude estimate of what is really happening within the brain.
Now researchers at MIT have developed a way of tracking the concentration of calcium ions, which are more closely related to neurons firing than the much slower and less accurate conventional fMRI. The team developed a sensor that consists of two separate particle types that bind to each other when encountering calcium concentrations. One is synaptotagmin, a protein that binds with calcium, and the other is iron oxide that has been magnetized, but which binds to synaptotagmin when there’s calcium around.
When the two types of particles come together, they look different under MRI than when they’re apart. The researchers tried this out in lab rats, activating activity in the same part of the brain where the new sensors were injected. The investigators used fMRI to track the temporal changes in the produced image. They demonstrated that their calcium spotting system works as expected, opening the door for more nuanced research into the workings of our most mysterious organ.
Study in Nature Nanotechnology: Calcium-dependent molecular fMRI using a magnetic nanosensor…
Via: MIT…