American and Chinese scientists reveal how the brain communicates with the intestine in a roundworm to regulate its longevity, according to a study published Tuesday in the Genes & Development journal.
Shawn Xu, the paper's correspondent author and a professor at the University of Michigan, and researchers from China's Huazhong University of Science and Technology, used different environmental temperatures, which are known to affect roundworms' lifespan, to investigate 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 that senses 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, a neurotransmitter, into the worm's gut.
The serotonin then 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. There, it blocks the activity of that 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 uses that information to communicate with the intestine about aging.
Also, these signals can be broadcast from the intestine to other parts of the body, allowing the neurons to regulate body-wide aging.
Previous researches have focused mainly on how signals from the gut can affect neurological functions, but much less is known about how the brain-gut signaling affect certain biological process, such as aging.
"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.
