A recent Chinese study observed the process by which our brain triggers vomiting and nausea after eating contaminated food.
- In cases of food poisoning, vomiting may be accompanied by cramps, diarrhea, fever and headache.
- It is recommended to hydrate regularly as well as to consume rice, pasta and bananas during food poisoning in order to facilitate the work of the intestine.
Food poisoning is caused by consuming food or water contaminated with bacteria, viruses or parasites. After detecting their presence, the brain triggers various defense reactions such as nausea and vomiting. The goal? Rid the body of these toxins.
In a study published in the journal Cell, researchers from the National Institute of Biological Sciences in Beijing (China) looked at the process by which our brain triggers vomiting after consuming contaminated products. For a long time, this biological reaction remained mysterious in the eyes of the scientific world.
“The neural mechanism of retching is similar to that of vomiting”
For this research, the team administered staphylococcal enterotoxin A (SEA), a bacterium that is responsible for foodborne illness in humans, to mice. The scientists then observed the defensive reactions of the rodents’ organisms.
According to the study authors, the mice do not vomit, but they gag. “The neural mechanism of retching is similar to that of vomiting. In this experiment, we successfully constructed a paradigm to study toxin-induced vomiting in mice, which allows us to examine defensive responses from the brain to toxins at the molecular and cellular levels”explained Peng Cao, co-author of the study and researcher at the National Institute of Biological Sciences in Beijing.
The researchers found that the mice given the bacteria opened their mouths unusually compared to the control group given salt water. During these episodes, the diaphragm and abdominal muscles of mice treated with staphylococcal enterotoxin A contracted simultaneously.
Serotonin: the neurotransmitter responsible for vomiting
Staphylococcal enterotoxin A activated the release of serotonin, a neurotransmitter, which is involved in communication between the gut and the brain. This substance is released by enterochromaffin cells in the wall of the intestinal lumen. It then binds to receptors on vagal sensory neurons located in the gut that transmit signals to Tac1+ neurons of the dorsal vagal complex (DVC) in the brainstem. It is this process that results in the defense mechanism including nausea and vomiting.
To reach this conclusion, the scientists inactivated Tac1+ neurons in mice receiving staphylococcal enterotoxin A. These rodents then had less nausea than the control group of mice.
In a majority of cases, patients undergoing chemotherapy suffer from nausea and vomiting. During the study, the researchers also injected the mice with doxorubicin, a chemotherapy drug. The rodents felt nauseous, but the team then inactivated the Tac1+ neurons of the enterochromaffin cells. The retches were then reduced. “Thanks to this study, we can now better understand the molecular and cellular mechanisms of nausea and vomiting, which will help us develop better drugs.“said Peng Cao.
