New technique tracks brain function 60 times faster than traditional fMRI
The speed of the human brain is remarkable. Almost immediately upon being exposed to stimuli, neurons are activated, prompting subconscious reactions and, a fraction of a second later, thought. But the speed at which we can noninvasively follow brain function using an MRI is not as impressive. Functional MRI (fMRI), which measures changes in blood-oxygen levels, has revolutionized neuroscience by revealing functional aspects of the brain, but the vascular changes fMRI measures can take up to six seconds in humans — a veritable eon in brain time.
In a paper published in Science Advances, investigators from Brigham and Women’s Hospital, in collaboration with colleagues at King’s College London, the French human-health research organization Inserm, and elsewhere, have discovered a fundamentally new way to measure neuronal function using a technology that can pick up changes in the brain as much as 60 times faster. The team presents data from preclinical studies indicating that the technique can track brain activity within 100 milliseconds of stimuli being applied.
Magnetic resonance elastography (MRE), which creates maps of tissue stiffness using an MRI scanner, was developed in 1995 by researchers at the Mayo Clinic and was initially applied to studying liver fibrosis. “MRE has been applied to a number of things, including, more recently, the brain,” said Sam Patz, a physicist in the Brigham’s Department of Radiology and a professor of radiology at Harvard Medical School. “But no one had observed regional changes in brain-tissue stiffness in relation to neuronal activity. We didn’t even know that happened in the brain on a scale that would be reflected in an MRI scan.”