Research from New University of Illinois in rats shows that the entire brain responds to the gut, especially the small intestine, through neural connections.
To map the connections, the researchers introduced viruses that “love” neurons in the small intestine of rats and them as they moved from neuron to neuron along it. pneumogastric nerve and spinal nerves throughout the brain. The idea was that the movement of viruses mimics normal signals through neurons from the gut to the brain and back.
The study represents the first complete map of neural connections between the small intestine and the entire brain. The involvement of cognitive and emotional centers suggests that the thinking brain can sometimes affect the feeling that we are full as well as other digestive issues.
In addition to showing how extensive the connections between the small intestine and the brain are, the study revealed a rare documented feature of neurons.
Scientists have long speculated that stimuli from the gut, or anywhere else in the body, travel to the brain along a set of neurons (sensory neurons), with instructions from the brain to travel back to a separate set of neurons (motor neurons). But in their mapping study, the researchers found that some of the neurons – about half – are capable of sending both sensory and motor signals, which “talk” to each other in the same neuron.
The crosstalk pattern (meaning that 50% of neurons have both sensory and motor signaling ability) showed another study of mapping neural connections between adipose tissue and the brain.
Researchers point out that the new data for the crosstalk pattern could suggest a general architecture of neural networks between body and brain.
The study was published in the journal Autonomic Neuroscience: Basic and Clinical.