As a medical resident specializing in psychiatry, Karl Deisseroth was tired of being served neurotransmitter soup. Brains are intricate, electrical structures, so why is mental illness so often framed as a chemical imbalance? To him, it made more sense to think in terms of circuits. "Talking to a patient that's depressed," he says, "you get a sense that activity is not flowing appropriately."
Deisseroth wanted to know how signals move through interconnected cells, but common techniques to study living brains - PET and functional MRI - were too slow and imprecise to study neural networks effectively. They take measurements in seconds and millimeters rather than in milliseconds at the level of individual cells.
As a graduate student and postdoc, Deisseroth dissected the molecular interactions that occur as neurons respond and adapt to stimuli. In particular, he and colleagues found that repeated stimulation in neurons stabilize the MAP kinase pathway to ...
