Helsinki: Microplastic particles are not only capable of spreading throughout the body but can also reach the brain, according to a report by researchers at the University of Eastern Finland. Global plastic production rises annually, and over time a significant portion breaks down into minute particles known as microplastics, which can enter the human body through drinking water, food, and air. According to Oman News Agency, previous research has shown that these particles can cross the blood-brain barrier-the brain's natural defense against harmful substances in the blood-but their precise effects on healthy neurons remain poorly understood. In the study, researchers tested polystyrene particles of different sizes-50, 100, and 250 nanometres-on living nerve cells taken from mouse embryos. The smallest particles (50 nanometres) led to abnormal growth of neuronal branches without causing cell death, but altered the pattern of cell development, the results showed. Genetic analysis revealed the activation of g enes associated with the growth of neuronal projections. Researcher Veronika Gurova said particle size is as important as concentration in determining biological effects, explaining that ultrafine particles can induce changes in neuronal behavior. The gene responsible for calcium-dependent elongation of neuronal branches was notably active in cells exposed to the smaller particles, the analysis also showed. Microplastics can infiltrate the brain and affect its development even at low exposure levels, the researchers said. Although short-term exposure did not cause direct damage or clear functional disturbances, the long-term effects remain unknown. Scientists warn that continuous exposure to these particles over many years in real-world settings could have unexpected consequences for brain health, calling for further studies to better understand the mechanisms involved.