Lee, T. et al. Science 344, 533–535 (2014).

Dopamine is an important neurotransmitter in the brain, but a detailed understanding of the role that dopamine signaling plays in motivation and addiction, as well as in disease, requires methods for detecting stimulus-evoked dopamine release at high spatial and temporal resolution. Lee et al. combined magnetic resonance imaging (MRI) with a specific dopamine sensor to identify brain regions that respond to microstimulation in the lateral hypothalamus, a region that has been implicated in addiction. The dopamine sensor is a paramagnetic heme protein called BM3h-9D7, which has been evolved for sensitivity to dopamine and can be used as a contrast agent for functional MRI. The researchers used the technique to construct a quantitative map of dopamine release in the nucleus accumbens upon stimulation in the lateral hypothalamus.