T Nation

Brain-Stomach Connection Mapped


#1

Oct 3, 2006 ? NEW YORK (Reuters Health) - Scientists from Brookhaven National Laboratory in Upton, New York have identified brain-stomach connections that motivate the desire to over indulge in food.

Specifically, the research suggests an important role for the hippocampus ? the part of the brain associated with motivation, emotion, and memory formation ? in controlling "emotional eating." The work may one day lead to new ways to prevent or treat obesity.

"This study opens new territory in understanding how the body and brain connect to each other, and how this connection is tied to obesity," said Dr. Gene-Jack Wang in a Brookhaven-issued statement accompanying the study in the Proceedings of the National Academy of Sciences.

"We were able to simulate the process that takes place when the stomach is full and for the first time we could see the pathway from the stomach to the brain that turns 'off' the brain's desire to continue eating," Wang explained.

To look at how the human brain responds to "fullness" cues, the scientists implanted a gastric stimulator in seven obese individuals for one to two years. The investigational device provides low levels of electrical stimulation to the vagus nerve, causing the stomach to expand and send "fullness" messages to the brain. The device has been shown to curb the desire to eat.

The subjects underwent brain scans with the stomach stimulator in the on and off mode. Prior to the scans, the volunteers were injected with a radioactive molecule that would light up on the scan so the researchers could track brain metabolism.

"We found that implantable gastric stimulators induced significant changes in metabolism in brain regions associated with controlling emotions, effectively shutting down these obese subjects' desire to eat," said Wang.

The changes were most pronounced in the hippocampus, where metabolism was 18-percent higher with the stomach stimulator turned on.

The stomach stimulator also sent messages of fullness to brain circuits in the frontal cortex and striatum, brain regions linked to craving and desire for drugs in addicts.

With the gastric stimulator on, the subjects self-reported "emotional eating" scores were 21-percent lower than when the stimulator was off.

"This provides further evidence of the connection between the hippocampus, the emotions, and the desire to eat, and gives us new insight into the mechanisms by which obese people use food to soothe their emotions," Wang said. "This new pathway should be explored in further studies to determine if there are any implications for treating or preventing obesity."

SOURCE: Proceedings of the National Academy of Sciences, October 2, 2006.
http://abcnews.go.com/US/wireStory?id=2521379


#2

Eh, this is kind of neat but their conclusions are old concepts. There are many peptide hormone drugs in the making right now that have been shown to have dramatic effects on affecting various aspects of the brain-stomach-feeding relationship.

Oxyntomodulin, GLP-1 and glucagon are 3 fairly well studied and known examples. I work with GLP-1 and glucagon currently as a grad. student researcher.

They will be prominent weight loss and/or antidiabetic drugs in the future I suspect. Prominent as in one of those billion dollar profit drugs...

But on the theme of T-Nation, I also see a great potential for body builders as well. GLP-1 enhances glucose-dependent insulin secretion, slows gastric emptying, increases B-cell proliferation, curbs your appetite, and is very effective/helpful at "prepping" your body (glycogen storages) for fasting cycles. Very interesting indeed... especially for someone who wants to run a cut cycle and not hurt their body's homeostasis that much. Taking a weekly dose of some long acting GLP-1 should provide a serious advantage for bodybuilders who need to loose weight quickly and healthily.

GLP-1 is so cool because it has receptors in, from what I know off the top of my head, your brain, intestines, and pancreas. So it has many effects. There are also some recent 2000- papers about how it clears Alzheimer's plaques, protects against them and clears excess brain-iron levels. I'm not sure if that stuff is legit (NIH funded; seems ok), but if it is, expect this gut hormone to be big.

The prominent form of GLP-1 on the market right now, exendin-4, has a few problems (short half life, enzyme cleavage, stability, nauseau) but the story behind the drug is amazing. A desert lizard only eats a few times a year and produces no insulin when fasting, but when it does eat, it turns on cells that release exendin-4 so that it's body can make insulin again.

Ingenious if you ask me. Glucagon.com has great information about these hormones for any one interested, or send me a PM, I will talk peptides all day.