Microplastics Found to Cause Behavioral Changes and Inflammatory Responses in Mice
Plastics, particularly microplastics, have become one of the most pervasive pollutants on Earth. These tiny particles find their way into our air, water systems, and food chains, causing significant harm to marine organisms. While there is a growing awareness of the prevalence of microplastics in the environment, very few studies have explored their potential health impacts on mammals. Recognizing this knowledge gap, Professor Jaime Ross and her team at the University of Rhode Island set out to investigate the neurobehavioral effects and inflammatory responses caused by exposure to microplastics in mice, as well as their accumulation in various tissues, including the brain.
According to Ross, the infiltration of microplastics was as extensive within the body as it is in the environment, leading to behavioral changes, particularly in older test subjects. Their study involved exposing both young and old mice to different levels of microplastics in their drinking water over a three-week period. The team discovered that this exposure resulted in behavioral changes and alterations in immune markers in the liver and brain tissues of the mice. Notably, the behavior of the mice resembled symptoms of dementia in humans, and the effects were more pronounced in the older animals.
What we found was striking, said Ross. Even at relatively low doses of microplastics, these changes occurred within a short period. Understanding the life cycle of microplastics within the body is crucial, especially as individuals age. Are older individuals more susceptible to systemic inflammation caused by microplastics? Can their bodies efficiently eliminate these particles? Do their cells respond differently to these toxins?
To gain insights into the physiological systems affected by these behavioral changes, Ross’s team investigated the extent of microplastic exposure within various organs, including the brain, liver, kidney, gastrointestinal tract, heart, spleen, and lungs. Astonishingly, they discovered that microplastic particles had started to bioaccumulate in every organ, including the brain, as well as in bodily waste.
Ross stated, While it was expected to detect microplastics in the gastrointestinal tract, liver, and kidneys when delivered orally via drinking water, finding them in tissues like the heart and lungs suggests that these particles are circulating systemically. It is particularly remarkable that the microplastics penetrated deep into brain tissue, considering the brain blood barrier is designed to be highly impermeable.
Moreover, the infiltration of microplastics into the brain is believed to contribute to a decrease in glial fibrillary acidic protein (GFAP), a protein that plays a crucial role in various brain cell processes. The decrease in GFAP has been associated with early stages of neurodegenerative diseases, such as Alzheimer’s disease, and depression.
The study conducted by Professor Ross and her team was published in the International Journal of Molecular Science. The research was supported by various organizations, including the Rhode Island Medical Research Foundation, Plastics Initiative, George and Anne Ryan Institute for Neuroscience, and the Rhode Island Institutional Development Award Network of Biomedical Research Excellence.
Moving forward, Ross intends to delve deeper into the impact of plastics on the brain and explore how they may disrupt the brain’s ability to maintain homeostasis. Understanding the link between plastic exposure and neurological disorders, including Alzheimer’s disease, is a critical area of study.
The findings of this research highlight the urgent need for greater attention to the harmful effects of microplastics on mammals. With these plastics being so prevalent in our environment, it is crucial to further explore their ramifications on human health. Awareness and action are necessary to mitigate the widespread pollution caused by microplastics and safeguard both wildlife and human populations.
