MRI sensor responds to dopamine

According to the MIT, functional magnetic resonance imaging (fMRI) measures blood flow, which is a slow and indirect readout of neural activity. When a brain region becomes active, blood vessels in that region dilate, causing increased blood flow to the site. Iron found in the blood’s haemoglobin mediates a magnetic change that is detected by MRI.

MRI sensors that quickly and directly respond to chemicals involved in the brain’s information processing would provide a much more precise measurement of brain activity.

‘We have designed an artificial molecular probe that changes its magnetic properties in response to the neurotransmitter dopamine,’ said Alan Jasanoff, an associate professor of biological engineering at the MIT and senior author of the Nature Biotechnology paper describing the work. ‘This new tool connects molecular phenomena in the nervous system with whole-brain imaging techniques, allowing us to probe very precise processes and relate them to the overall function of the brain and of the organism. With molecular fMRI, we can say something much more specific about the brain’s activity and circuitry than we could using conventional blood-related fMRI.’