The gut nervous system has come to be called a “second brain”:
How the ‘second brain’ — the enteric nervous system in our gut — communicates with our first brain has been one of the most challenging questions faced by enteric neuroscientists, until now.
New research from Flinders University has discovered how specialised cells within the gut can communicate with both the brain and spinal cord, which up until now had remained a major mystery.
“The gut-brain axis consists of bidirectional communication between the brain and the gut, which links emotional and cognitive centres of the brain with peripheral intestinal functions,” says study author Professor Nick Spencer from the College of Medicine and Public Health.Flinders University, “How the gut communicates with the brain” at ScienceDaily (March 23, 2022)
It’s not clear why it should not all be thought of as one brain system:
“Within the gut wall lie specialised cells called enterochromaffin (EC) cells that produce and release hormones and neurotransmitters in response to particular stimuli that are ingested when we eat,” says Professor Spencer.
“These EC cells release the vast majority of serotonin into the body, so our study has uncovered a major clue into how the food we eat stimulates the release of serotonin, which then acts on the nerves to communicate with the brain.
“There is a direct connection between serotonin levels in our body and depression and how we feel. So, understanding how the gut EC cells communicate with the brain is of major importance.”
The team made the discovery using a neuronal tracing technique developed in their lab, not used anywhere else in the world, allowing them to see the sensory nerve endings with clarity, for the first time, in the gut wall.
“This has not been possible, until now, because there were so many other types of nerves also present in the gut — it’s like finding a needle in a haystack,” says Professor Spencer.Flinders University, “How the gut communicates with the brain” at ScienceDaily (March 23, 2022)
But we’re not here just to quibble. No wonder that, in order to account for all this specified complexity, evolutionary biologists must elevate natural selection into some form of magic, then persecute non-believers.
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