Present everywhere in the environment, microplastics can be found in human tissues. In mice, their impact on the nervous system leads to behavioral changes.
- Microplastics are present everywhere in the environment, and can be found in human tissues.
- A study in mice shows that they can enter brain tissue and cause changes in certain protein levels.
- This can lead to behavioral changes and could increase the risk of neurodegenerative disease.
Microplastics are everywhere: in the air, in water, in food. This means that we ingest them and that they are present in our body. But what are their effects on our health? According to a new study published in International Journal of Molecular Sciencesthis pollution can affect our nervous system and modify our behavior.
Microplastics: better understanding their effects on human health
“Current research suggests that these microplastics are transported throughout the environment and can accumulate in human tissues; However, research into the health effects of microplastics, particularly in mammals, is still very limited, explains Jaime Ross, lead author of the study and assistant professor of biomedical and pharmaceutical sciences at the Ryan Institute for Neuroscience in the United States. This led our group to explore the biological and cognitive consequences of exposure to microplastics.” The scientist and her team were interested in their effects on the brain and on inflammation.
Microplastics: changes in mouse behavior
The American researchers exposed young and old mice to different levels of microplastics in drinking water for three weeks. They found that exposure to microplastics induced behavioral changes and alterations in immune markers in liver and brain tissues. “The mice studied began to move and behave in peculiar ways, exhibiting behaviors close to dementia in humansnote the authors. The results were even more striking in older animals.” The researchers say they have been “hit” by these findings, especially since they were not high doses of microplastics.
Microplastics present in all organs of mice
“No one really understands the life cycle of these microplastics in the body, so we particularly want to know what happens as we age.specifies Jaime Ross. Are you more susceptible to systemic inflammation from these microplastics as you age? Can your body get rid of them that easily? Do your cells respond differently to these toxins?” The second part of the study therefore consisted of observing the effects of these microplastics on tissues. The researchers dissected the brains, liver, kidneys, gastrointestinal tract, heart, spleen and lungs of the mice. “The particles began to bioaccumulate in all organs, including the brain, as well as in bodily waste.”they note.
Microplastics: a risk of neurodegenerative disease?
According to them, the presence of these substances in the heart and lungs suggests that they then circulate in the body. “The brain blood barrier is believed to be very difficult to penetrate, they recall. This is a protective mechanism against viruses and bacteria, but these particles were able to get in.” However, their presence reduced the quantity of a protein, called glial fibrillary acidic protein (called ‘GFAP’), involved in different brain cellular processes. “Decreased GFAP has been associated with the early stages of certain neurodegenerative diseases in mouse models, such as Alzheimer’s disease, as well as depression. Jaime Ross therefore wishes to continue her work to better understand the effects of microplastics on the risk of neurodegenerative disease.
