Neurology Explains What Happens to the Brain Whenever We Throw Up

Vomiting is a bodily process that involves the forceful removal of the contents of the stomach and sometimes the intestines. It is regulated by the brain and its designated vomiting center. Vomiting can occur when the body needs to expel toxins from ingested food that has been contaminated with harmful bacteria, as per News Medical.

Researchers studied this process in mice, following the movement of substances from the gut to the brain. Interestingly, mice do not typically vomit, possibly due to their relatively long esophagus and weak muscle strength in proportion to their body size.

While mice do not vomit, they do exhibit a behavior known as retching, which is similar to vomiting in humans. Researchers used this behavior in mice as a model for studying the biological signals involved in food poisoning. This novel research has been reported in the journal Cell.

Brain and Gut Reaction

By administering a bacterial toxin called Staphylococcal Enterotoxin A (SEA) to mice, which is also responsible for foodborne illness in humans, the researchers were able to observe the defensive responses of the brain to toxins at the molecular and cellular levels. The mice displayed wide mouth-opening actions and contractions of the diaphragm and abdominal muscles, similar to what is seen in dogs during vomiting. This experiment allowed the researchers to establish a paradigm for studying toxin-induced retching in mice.

Using a technique called fluorescent labeling, the researchers found that the bacterial toxin SEA activated the release of the neurotransmitter serotonin in the intestine. This serotonin then triggered a chemical process that sent a message through the vagus nerves, which are the main connections between the gut and the brain, to specific cells called Tac1+DVC neurons in the brainstem.

When these Tac1+DVC neurons were artificially deactivated, the mice displayed less retching. The researchers also observed a similar effect when they induced nausea in mice with the chemotherapy drug doxorubicin. When the Tac1+DVC neurons were switched off or serotonin production was stopped, the mice retched significantly less compared to the control group.

woman having a panic attack using paper bag to calm herself

(Photo : Getty Images | Peter Dazeley)
A woman vomiting

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Human Intestinal Hormones

This study has provided new insights into the molecular and cellular mechanisms underlying nausea and vomiting, which could lead to the development of more effective medications. The researchers discovered that intestinal tissues containing enterochromaffin cells are responsible for releasing serotonin in the gut, and future studies could examine how toxins interact with these cells to trigger the vomiting process. Overall, this research could help improve our understanding of the biological basis of vomiting and how to effectively treat it.

The findings from this research could potentially provide new insights into both food poisoning and chemotherapy. The results suggest that the body produces similar defensive responses to both, but further research in humans would be needed to confirm the relevance of these findings to human biology. The research may lead to the development of more effective anti-nausea medications for people undergoing chemotherapy, which could help reduce the unpleasant side effects of these drugs. Ultimately, this study could contribute to a better understanding of the biological basis of vomiting and how to effectively treat it.

In addition to encountering harmful substances in food, humans encounter a wide range of pathogens, and our bodies have similar mechanisms in place to expel these toxic substances. For example, coughing is a response that helps remove the coronavirus from the body. As per neurobiologist Peng Cao from the National Institute of Biological Sciences in Beijing, this is a new and exciting area of research that involves understanding how the brain senses the presence of pathogens and initiates responses to remove them, as the doctor mentioned in a statement from Eurekalert.