ISLAMABAD, JUNE 15 (online): A new study reveals how neurons in the gut wall relay sensory information to the spinal cord and brain, which may influence mood and well-being.
The enteric nervous system (ENS) sometimes referred to as the “second brain” is the nervous system of the gut.
It contains some 500 million neurons and controls important reflexes, such as peristalsis, the contraction of muscles in the gut to enable digestion. It is also responsible for the secretion of digestive enzymes that help break down food.
The ENS is also a critical part of the gut-brain axis, through which the gut communicates with the brain — and the vagus nerve is particularly essential for conveying information about the intestines to the brain.
The gut-brain axis performs several functions. The majority of serotonin, a neurotransmitter associated with mood, is found in the gut, for example.
In a new study, in Adelaide, Australia, have identified a new way that neurons in the gut wall can activate neurons that connect to those in the spinal cord.
The researchers recorded the electrical activity of the viscerofugal neurons. They found that the firing of these neurons was associated with changes in the activity of the smooth muscle of the colon.
The neurons fired in a highly synchronized way, which was associated with the parallel activation of neurons in the spinal cord.
This suggests that viscerofugal neurons relay activity from the nervous system of the gut to the sympathetic nervous system — in other words, the spinal cord and brain.
“The new study has uncovered how viscerofugal neurons provide a pathway so our gut can ‘sense’ what is going on inside the gut wall, then relay this sensory information more dynamically than was previously assumed to other organs, like the spinal cord and brain, which influence our decisions, mood and general well-being,” explains Prof. Spencer.