Researchers at the University of Tsukuba, in Japan, have discovered that exposure to light of sea urchin larvae generates variations in their digestion, even in the absence of food stimuli. The finding confirms that the brain can regulate digestive processes through information from light stimulation.
Light is known to be used by many life forms as an important biological signal, including animals with visual and non-visual systems. However, the new study suggests that neurons may have initially evolved to regulate digestion based on information obtained directly from light. Should we give more importance then to the influence of the brain on digestive processes?
According to a press release , Japanese researchers found that stimulation of sea urchin larvae through light led to changes in the function of the digestive system, although no direct food-related stimuli have been recorded. In the experiment carried out by the scientists, it was found that exposure to light caused the opening of the pylorus, a vital component in the digestive tract.
Sea urchins, also known under the scientific name of echinoids, are found on the seabed, between rocks and on coral reefs. They feed on algae, dead fish, sponges, barnacles, mussels, and other varieties of animals and plants that can be found in the seas around the world.
NEURONS AND THEIR IMPACT ON DIGESTION
The study’s findings indicate that an early function of neurons may have been the regulation of the digestive tract in our evolutionary ancestors. Because food consumption and nutrient absorption are critical to survival, the development of a sophisticated gut-brain regulatory system may have been an important step in animal evolution.
To delve into the causes of changes in digestion produced by exposure to light in sea urchins, the researchers traced the activity of proteins in the Opsin family. These proteins are crucial to appreciate the evolution of the use of light as an external signal in all types of organisms, since they are present even in life forms without visual systems.
They found that there are serotonin-producing neurons that work integrated with cells related to the Opsin proteins. This joint activity facilitates the light-stimulated release of nitric oxide, which acts as a neurotransmitter. This complex brain process culminates in the variations observed in the digestive system of sea urchins.
BRAIN AND INTESTINE: MUTUAL INFLUENCE
The brain-intestine axis is being increasingly considered by scientists as one of the most important systems in the organization of human beings and other living beings. Thus, some specialists speak of the intestine as a “second brain”, given its importance in multiple vital processes.
In addition to the brain’s regulation of digestive processes, as this new research published in the journal BMC Biology explores, a reciprocal influence has also been discovered: the intestinal microbiota would be capable of modulating the brain , causing changes and modifications that are putting in check to many of the current paradigms of medicine, biology and science in general.
