Novel MRI sensor provides molecular view of the brain

CAMBRIDGE, Mass. " MIT neuroscientists have designed a new MRI sensor that responds to the neurotransmitter dopamine, an achievement that may significantly improve the specificity and resolution of future brain imaging procedures. Although functional magnetic resonance imaging (fMRI) has enhanced our understanding of brain function since it was first introduced about 20 years ago, the technology actually 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 hemoglobin mediates a magnetic change that is detected by MRI. But MRI sensors that directly and rapidly respond to chemicals involved in the brain"s information processing would provide a much more precise measurement of brain activity. This technology has not been available until now.