Nav: Home

Scientists find evidence of link between diesel exhaust, risk of Parkinson's

May 20, 2020

A new UCLA study in zebrafish identified the process by which air pollution can damage brain cells, potentially contributing to Parkinson's disease.

Published in the peer-reviewed journal Toxicological Sciences, the findings show that chemicals in diesel exhaust can trigger the toxic buildup of a protein in the brain called alpha-synuclein, which is commonly seen in people with the disease.

Previous studies have revealed that people living in areas with heightened levels of traffic-related air pollution tend to have higher rates of Parkinson's. To understand what the pollutants do to the brain, Dr. Jeff Bronstein, a professor of neurology and director of the UCLA Movement Disorders Program, tested the effect of diesel exhaust on zebrafish in the lab.

"It's really important to be able to demonstrate whether air pollution is actually the thing that's causing the effect or whether it's something else in urban environments," Bronstein said.

Testing the chemicals on zebrafish, he said, lets researchers tease out whether air pollution components affect brain cells in a way that could increase the risk of Parkinson's. The freshwater fish works well for studying molecular changes in the brain because its neurons interact in a way similar to humans. In addition, the fish are transparent, allowing scientists to easily observe and measure biological processes without killing the animals.

"Using zebrafish allowed us to see what was going on inside their brains at various time-points during the study," said Lisa Barnhill, a UCLA postdoctoral fellow and the study's first author.

Barnhill added certain chemicals found in diesel exhaust to the water in which the zebrafish were kept. These chemicals caused a change in the animals' behavior, and the researchers confirmed that neurons were dying off in the exposed fish.

Next, they investigated the activity in several pathways in the brain known to be related to Parkinson's disease to see precisely how the pollutant particles were contributing to cell death.

In humans, Parkinson's disease is associated with the toxic accumulation of alpha-synuclein proteins in the brain. One way these proteins can build up is through the disruption of autophagy -- the process of breaking down old or damaged proteins. A healthy brain continuously makes and disposes of the proteins it needs for communication between neurons, but when this disposal process stops working, the cells continue to make new proteins and the old ones never get cleared away.

In Parkinson's, alpha-synuclein proteins that would normally be disposed of pile up in toxic clumps in and around neurons, eventually killing them and interfering with the proper functioning of the brain. This can result in various symptoms, such as tremors and muscle rigidity.

Before exposing the zebrafish to diesel particles, the researchers examined the fishes' neurons for the tell-tale pouches that carry out old proteins, including alpha-synuclein, as part of the autophagy disposal operation and found that the process was working properly.

"We can actually watch them move along, and appear and disappear," Bronstein said of the pouches.

After diesel exposure, however, they saw far fewer of the garbage-toting pouches than normal. To confirm that this was the reason brain cells were dying, they treated the fish with a drug that boosts the garbage-disposal process and found that it did save the cells from dying after diesel exposure.

To confirm that diesel could have the same effect on human neurons, the researchers replicated the experiment using cultured human cells. Exposure to diesel exhaust had a similar effect on those cells.

"Overall, this report shows a plausible mechanism of why air pollution may increase the risk of Parkinson's disease," Bronstein said.
-end-
The study's other authors are Sataree Khuansuwan, Daniel Juarez, Hiroma Murata and Jesus Araujo, all of the department of neurology in the David Geffen School of Medicine at UCLA.

The research was supported by the National Institute of Environmental Health Sciences, the National Institutes of Health, the Levine Foundation and the Parkinson's Alliance.

University of California - Los Angeles Health Sciences

Related Neurons Articles:

Paying attention to the neurons behind our alertness
The neurons of layer 6 - the deepest layer of the cortex - were examined by researchers from the Okinawa Institute of Science and Technology Graduate University to uncover how they react to sensory stimulation in different behavioral states.
Trying to listen to the signal from neurons
Toyohashi University of Technology has developed a coaxial cable-inspired needle-electrode.
A mechanical way to stimulate neurons
Magnetic nanodiscs can be activated by an external magnetic field, providing a research tool for studying neural responses.
Extraordinary regeneration of neurons in zebrafish
Biologists from the University of Bayreuth have discovered a uniquely rapid form of regeneration in injured neurons and their function in the central nervous system of zebrafish.
Dopamine neurons mull over your options
Researchers at the University of Tsukuba have found that dopamine neurons in the brain can represent the decision-making process when making economic choices.
Neurons thrive even when malnourished
When animal, insect or human embryos grow in a malnourished environment, their developing nervous systems get first pick of any available nutrients so that new neurons can be made.
The first 3D map of the heart's neurons
An interdisciplinary research team establishes a new technological pipeline to build a 3D map of the neurons in the heart, revealing foundational insight into their role in heart attacks and other cardiac conditions.
Mapping the neurons of the rat heart in 3D
A team of researchers has developed a virtual 3D heart, digitally showcasing the heart's unique network of neurons for the first time.
How to put neurons into cages
Football-shaped microscale cages have been created using special laser technologies.
A molecule that directs neurons
A research team coordinated by the University of Trento studied a mass of brain cells, the habenula, linked to disorders like autism, schizophrenia and depression.
More Neurons News and Neurons Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.