Exploring how pollution might impact the brain
A reduction in sense of smell precedes certain neurological conditions, and pollution has been shown to increase the risk of these diseases. A new study attempts to link these findings together.
Over the years, researchers have begun to see links between pollution and neurological diseases, such as Parkinson's and Alzheimer's
Although evidence is mounting, scientists have not yet figured out how airborne particles might impact the brain.
Recently, researchers from Penn State University, PA, investigated possible links between pollution, our sense of smell, and neurological disease.
They published their findings earlier this week in the journal eLife.
To investigate, the researchers were particularly interested in the flow of cerebrospinal fluid (CSF).
CSF is a fluid that surrounds the central nervous system (CNS), which comprises the brain and spinal cord. Classically, it was thought to act as a buffer that protects the CNS, but, over time, scientists have discovered more roles.
Prof. Patrick Drew, one of the authors of the study, explains, "More and more it is realized that it does not just cushion the brain, but may also transfer stuff out of the brain and spinal column area."
The role of CFS in disease
Researchers are growing increasingly interested in the CSF's role in waste clearance, and how it flows around the CNS. To date, researchers are not clear about what manages the production and outflow of CFS.
Neurological conditions, such as Parkinson's and Alzheimer's, are characterized by a buildup of faulty or misshapen proteins; perhaps CSF clearance could play a part.
The scientists wanted to understand how pollution in the air that we breathe influences the CSF and, therefore, refuse collection within the brain; but how would airborne compounds reach the CSF?
Another author of the study, graduate student Jordan N. Norwood, explains his first clue: "I was trying to label cerebrospinal fluid with a dye for another experiment. We started seeing this dyed cerebrospinal fluid drain out through the nose."
Although surprising, Norwood was not the first person to have speculated that CSF might exit the brain through the nose. When he looked through old research papers, there were a few references to this possibility.
The scientists also noted that researchers have already shown that a reduced sense of smell is sometimes an early sign of neurological conditions. For instance, a study published in Neurology concluded that poor performance in an odor identification test might, one day, be a useful way to predict Alzheimer's before the classic symptoms appear.
