Can't resist eating while crossing a fast food shop on the road? It's because of your hyperactivated 'Hunger Hormone', revealed a new study.
A recent study published in the Journal eLife
has found that hippocampus, a brain region important for learning and memory control, uses ghrelin as a signal to engage in learned feeding behavior. Ghrelin is a hormone released from the stomach that increases appetite.
‘Ghrelin, a hunger hormone communicates with neurons in the hippocampus to stimulate appetite and these neurons then communicate with the hypothalamus to produce the molecule orexin, which promotes hyperphagia, or excessive eating.
A team of researchers from the University of Southern California, United States analyzed a group of rats for their feeding behavior. They put these rats on a restricted feeding timing, wherein the rats were offered food only for four hours a day. When rats got aware of their restricted feed, they started to learn the habit of over eating in a limited period.
They found that ghrelin hormone was responsible for the overeating behavior by stimulating another molecule called as orexin which is associated with excessive eating. Furthermore, ghrelin has also been found to increase the rate at which nutrients pass through the body. But it is best to happen slowly in order to create a feeling of fullness over longer periods of time.
"We are looking deep into the higher order functions of the brain to unpick not just which hormones are important for controlling our impulses but exactly how the signals and connections work," said lead author Scott Kanoski.
Researchers are currently working to reduce ghrelin's effect by genetically suppressing the activity of its receptor in the hippocampus by disrupting neurochemical signals that facilitate the consumption of large quantities of food.
Reference: Ted M Hsu, Scott E Kanoski et al. "Hippocampus ghrelin signaling mediates appetite through lateral hypothalamic orexin pathways," eLife, Dec 15, 2015, http://dx.doi.org/10.7554/eLife.11190