Dopamine D2 Receptor

Is Bariatric Surgery Really Brain Surgery?

Striatal Dopamine Links Gastrointestinal Rerouting to Altered Sweet Appetite

Signals from the duodenum to the striatum in the brain (left) are inhibited after gastric bypass (right), reducing the release of dopamine in the brain as a response to sugar. Source: Han et al, 2015, Cell Metabolism.

Years ago, the concept of metabolic surgery started wedging itself into the realm of bariatric surgery. While it’s absurd to say that a gastric bypass is brain surgery, a steady stream of research on the neuroscience of bariatric surgery certainly raises a key question: does this surgery modify the nervous system as much as much as the gastrointestinal system?

The latest in this line of research is a study of the effects of bariatric surgery on sugar cravings and dopamine release in the brain. In Cell Metabolism, Wenfei Han and colleagues demonstrated that bariatric surgery reduces cravings for sugar in mice by inhibiting dopamine release controlled through a neural pathway between the duodenum and the brain. Though more is needed to understand the full implications of this animal research, the authors say that their findings “point to a causal link between striatal dopamine signaling and the outcomes of bariatric interventions.”

Earlier this year in PLOS ONE, researchers published another animal study that showed how gastric bypass surgery could alter brain activity involved with expecting food to be rewarding and tasty.

The real question is not whether this is brain surgery, but rather how scientists can use these clues to develop new, smarter therapies that will correct the neurological basis for the chronic disease of obesity. It’s research like this that promises to make this disease much more manageable, and one day, curable.

Click here to read the study in Cell Metabolism and here to read more about the study.

Dopamine D2 Receptor, photograph © Daniel Ari Friedman / flickr

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November 28, 2015