CHICAGO, Feb. 28 (Xinhua) -- A study of the University of Michigan (UM) Life Sciences Institute shows that signaling between the intestine and brain can regulate a range of biological processes, thus affecting certain biological process, such as aging.
The study is published on Feb. 28 in the journal Genes & Development.
Though tests on Caenorhabditis elegans, or roundworms, whose nervous system is well-mapped, the researchers discovered that brain-gut communication leads to an "axis of aging," wherein the brain and intestines work together to regulate the worm's longevity.
Using different environmental temperatures, which are known to affect roundworms' lifespan, the researchers investigated how neurons process information about external temperature and transmit that information to other parts of the body. They identified two different types of neurons, one sensing warmth and the other coolness, that act on the same protein in the intestine, telling it to either slow down or speed up the aging process.
When the cool-sensing neuron detects a drop in temperature, it sets off a chain of communication that ultimately releases serotonin into the worm's gut. This serotonin prompts a known age-regulating protein, DAF-16, to boost its activity and increase the worm's longevity.
The warmth-sensing neuron, in contrast, sends a compound similar to insulin to the intestine, where it blocks the activity of the same DAF-16 protein, shortening the worm's lifespan.
Using these two paths, the brain is able to process cues from the external environment and then use that information to communicate with the intestine about aging.
Moreover, these signals can be sent from the intestine to other parts of the body, allowing the neurons to regulate body-wide aging.
As many of the key players in these reactions are conserved in other species, Shawn Xu, a professor of molecular and integrative physiology at the UM Medical School, believes this research may have implications beyond roundworms.
"From our findings, it's clear that the brain and gut can work together to detect aging-related information and then disseminate that information to other parts of the body," Xu said. "We think it's likely that this sort of signaling axis can coordinate aging not only in C. elegans, but in many other organisms as well."
