Researchers at Stanford University have successfully induced and relieved depression-like deficiencies in both pleasure and motivation in mice by controlling just a single area of the brain known as the ventral tegmental area. It is the first time that well-defined types of neurons within a specific brain region have been directly tied to the control of myriad symptoms of major depressive illness.
In the paper published in Nature on Dec. 12, Stanford bioengineer Karl Deisseroth, MD, PhD, and a team including postdoctoral scholars Kay Tye, PhD, and Melissa Warden, PhD, and research assistant Julie Mirzabekov have used a technique known as optogenetics to pinpoint a specific brain location that produces multiple depression-like symptoms. The region in question is the ventral tegmental area, or VTA, a source of dopamine and a central player in the brain’s internal motivation and reward systems.
“We have for the first time directly tied dopamine neurons in the VTA to controlling and relieving these very different and diverse symptoms,” said Deisseroth, the study’s senior author and a professor of bioengineering and of psychiatry and behavioral sciences. “While depression is a complex disease with still many unknowns, this knowledge may help launch new kinds of investigation into the pathways of depression in the brain, and develop concepts to help people suffering from depression.”
Deisseroth’s team was able to both induce and relieve multiple depression-like symptoms in laboratory mice by genetically modifying the dopamine neurons in the VTA to be sensitive to light. Using fiber optic cables inserted in rodents’ brains, they could then instantaneously produce and inhibit the depression-like symptoms by turning the light on and off. This research technique, developed by Deisseroth at Stanford in 2005, is known as optogenetics.
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