Study reveals architecture of the 'second brain,' the enteric nervous system

May 19 (UPI) -- Researchers hope a survey of the body's enteric nervous system will offer new insights into the nature of common gastrointestinal diseases like irritable bowel syndrome and chronic constipation.

The survey of body's "second brain" offered scientists a better understanding of the system's complex architecture, the arrangement of more than half a billion nerve cells spread throughout the human gut.

Researchers engineered target cells in mouse models to glow fluorescent, allowing the team of scientists to track nerve cells as they populated the gut during mouse development. The share the results of their analysis in the journal Science.

"The gut wall is home to many types of nerve cells which appear to be distributed randomly," Vassilis Pachnis, researcher at the Francis Crick Institute, said in a news release. "But despite this chaos, the neural networks of the gut are responsible for well organized and stereotypic functions such as production of stomach acid, movement of food along the gut, communication with immune cells and bacteria, and relay of information to the brain."

Pachnis and his colleagues wanted to understand how the organized functions of the enteric nervous system emerge from the network's seemingly chaotic architecture.

Researchers marked progenitor cells with different colors and watched as they divided and generated a variety of cell types. They found some progenitor cells produce only nerve cells, while other produce only glia, a type of nerve-supporting cell. Other progenitors produce both nerve and glia cells.

"We uncovered a set of rules that control the organization of the 'second brain' not just along a single gut layer but across the 3D space of the gut wall," said Reena Lasrado, a researcher in Vassilis's lab at Crick.

When scientists stimulated the nerve cells with small jolts of electricity, they found nerve cells derived from the same parent progenitor cells remain linked and respond in unison.

"Now that we have a better understanding of how the enteric nervous system is built and works, we can start to look at what happens when things go wrong particularly during the critical stages of embryo development or early life," Vassilis said. "Perhaps mistakes in the blueprint used to build the neural networks of the gut are the basis of common gastrointestinal problems."