Brain catastrophe: Scientists have tracked microplastic movement further than ever before.

More than 150 years have passed since humans first created plastic, and during this time, it has managed to inundate the planet and become one of the most significant pollutants on Earth. Previous studies have already shown that tiny plastic particles have been detected in water, air, soil, and even in the bodies of living organisms, according to Popular Science.

Research findings have indicated that synthetic microplastics are harmful to us; however, the medical community remains uncertain about how exactly plastic affects the health of animals, humans, and ecosystems as a whole. Meanwhile, a new study has enabled experts to visually track the movement of microplastics through the blood vessels of mice for the first time. The results of the study clearly demonstrate that the accumulation of microplastics in the brains of mice resembles a microscopic "car crash."

In a new study conducted by a team from Peking University in Beijing, scientists found data that expands existing research, demonstrating the potential neurotoxicity of microplastics. It is already known that nanoplastics can disrupt the blood-brain barrier, but how they induce brain function disturbances remains unclear.

During the study, the team employed a fluorescent imaging method, also known as two-photon microscopy. This allowed scientists to gain a clearer view of ingested microplastics in real-time.

The researchers created a small transparent window in the skulls of laboratory mice. They then used a tool to administer water containing tiny spheres of fluorescent polystyrene to the test subjects. Previous studies have recorded approximately 12 nanograms of microplastics per milliliter of blood in humans, so the researchers estimated a proportional amount of polystyrene for delivery to the mice. It is noteworthy that polystyrene is considered one of the most common types of plastic found in toys, packaging, and household appliances.

Next, the team observed what was happening in the brains of the mice. About three hours later, glowing cells began to appear in the blood vessels of the brain — the researchers discovered that this was a combination of neutrophils and macrophages, two immune system cells responsible for engulfing harmful foreign objects.

It is suggested that some nanoparticles of plastic likely became lodged in the many twists of tiny blood vessels around the cerebral cortex. However, most cells, according to co-author of the study, biomedical researcher Huiren Huang from Peking University, accumulated "like in a car crash."

Ultimately, these accumulations resembled clots, minimizing blood flow to the brains of the animals for several days or weeks. While some of these concentrations of microplastic cells disappeared over time, others were still detectable even after four weeks.

The authors of the study also caution that it is premature to directly apply this mechanism to human research systems. The fact is that humans and mice have different immune, coagulation, cerebrovascular, and cardiovascular systems, thus requiring further research to understand how tiny plastic particles penetrate the human brain and affect it.