Scientists around the world have made a lot of progress in understanding mental health conditions like autism, schizophrenia, and Alzheimer’s disease.
They have discovered many changes in genes and brain proteins that may explain why these conditions happen. But there are still some parts of the brain that remain a mystery. One of these is a protein called IDO2.
IDO2 is part of a chemical process in the brain that breaks down tryptophan, a nutrient found in foods like turkey, eggs, and cheese.
This process is called the tryptophan-kynurenine pathway, and it’s known to play a role in how the brain works. Problems in this pathway have been linked to mental health conditions, but the exact role of IDO2 was still unclear.
To learn more, a research team in Japan led by Associate Professor Yasuko Yamamoto studied this protein in mice. They compared normal mice with mice that had been changed so they no longer had the IDO2 gene.
These special mice are called IDO2 knock-out mice. The scientists wanted to see if removing IDO2 would change how the mice behaved or how their brains worked.
The results were very surprising. The mice without IDO2 acted in ways that looked like symptoms of autism. They had trouble getting used to new places, groomed themselves over and over again, and didn’t explore their environment much.
When it came to social behavior, these mice also struggled. They didn’t seem to learn from other mice and had trouble interacting. These problems are similar to what people with autism experience.
The researchers looked inside the brains of the mice to figure out why this was happening. They found that without IDO2, the brain’s chemical balance was off. This affected dopamine, a chemical that helps control mood, motivation, and learning. In areas of the brain that use dopamine, like the striatum and amygdala, the levels were different in the IDO2 knock-out mice.
They also found that another important chemical in the brain, called BDNF, was lower in the IDO2 knock-out mice. BDNF helps brain cells grow and connect with each other. Without enough BDNF, the brain cells couldn’t make strong connections.
Under the microscope, the researchers saw that the cells in these mice had fewer mature branches, which means the brain had trouble building proper pathways for communication.
Another key discovery was about microglia, which are cells in the brain that clean up and support other brain cells. In the IDO2 knock-out mice, these microglia became more aggressive, switching from a calm state to an active one that breaks down damaged cells. This may have made the brain less stable and more sensitive to problems.
To test whether IDO2 really caused these changes, the researchers tried adding IDO2 back into the knock-out mice. When they did this, the mice’s behavior became more like that of normal mice. This is strong evidence that IDO2 plays a big role in brain behavior.
To see if this also happens in people, they checked brain samples from over 300 people with autism. One teenage girl had a mutation in the IDO2 gene. While this doesn’t prove anything by itself, it shows that IDO2 might also matter in human cases of autism.
This research opens up new ways to understand and possibly treat mental health conditions. If scientists can learn more about IDO2, they might find better ways to help people with autism and other brain disorders in the future.
If you care about autism, please read studies about food additives and ADHD, and natural fixes for ADHD.
For more health information, please see recent studies about nutrition’s role in managing ADHD, and this type of food may contribute to autism.
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