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Students nab prize for work on “hunger hormone”

By Chris Lydgate ’90 on December 01, 2015 12:12 PM

Peckish? Ghrelin is probably flooding your hypothalamus right now.

A trio of Reed psych majors won a prize at a scientific conference last month for their research into ghrelin—sometimes known as the “hunger hormone.”

Biochem major Eliotte Garling ’18, bio-psych major Lia Zallar ’16, and psych major Hannah Baumgartner ’16 won the Neuroscience/Psychology Poster Prize at the 24th annual Murdock College Science Research Program held in Vancouver, WA, for their research into the mechanisms by which ghrelin affects appetite, metabolism, stress, and reward signaling.

Working with Prof. Paul Currie [psych], the students performed a series of experiments on rats to investigate the effects of ghrelin when injected into different parts of the brain.

"Ghrelin is interesting because it seems to play a role in a lot of different pathways-- stress and anxiety, metabolism, eating behavior, reward, and drug-seeking behavior," says Lia. "With our research, we’re trying to parse out these individual circuits and what part ghrelin plays in them."

They found that injecting ghrelin into one area of the brain made the rats ravenous—they ate up to three times as much as rats that received no ghrelin. They also found that injecting ghrelin into a different area of the brain made them crave alcohol. Aside from triggering episodes of gluttony, binge-drinking, and remorse in rodents, the research suggests that ghrelin plays a different role in the brain depending on its location.  

"Our lab and others have shown that ghrelin in the hypothalamus, a region of the brain highly linked with metabolism and eating behavior, is associated with increased food consumption," Lia says. "But what’s cool is that it doesn’t increase voluntary alcohol intake, which suggests that alcohol-seeking behavior is probably not mediated at all by caloric intake. To further support this idea, ghrelin introduced to areas of the brain linked with reward, which are outside of the hypothalamus and part of the mesolimbic reward pathway, does increase alcohol consumption but does not increase eating behavior. So basically ghrelin is associated with different behaviors when introduced to different brain circuits."

Prof. Currie was recently quoted in an article in Time about why you get "hangry."

The students’ project was titled “Brain-Cannula Mapping Investigations of Acyl Ghrelin in Metabolic, Limbic, and Reward Signaling” and is supported by the MJ Murdock Charitable Trust.