Fluid Movement Linked to Yawning
A study by UNSW Sydney and Neuroscience Research Australia suggests yawning may facilitate the movement of important fluids in the brain, offering potential insights into ageing and neurodegenerative diseases.
Using real-time MRI scans, researchers observed that yawning triggers a manoeuvre where cerebrospinal fluid (CSF) and venous blood move out of the skull, unlike during deep breathing where CSF flows into the skull.
Professor Lynne Bilston from UNSW’s School of Biomedical Engineering noted, “We observed that yawning is a body movement that can influence the flow of fluids around the brain.”
The Role of Cerebrospinal Fluid
Cerebrospinal fluid surrounds the brain and spinal cord, and its movement during yawning could aid in clearing waste from the brain, potentially impacting studies on Alzheimer’s, Parkinson’s, and dementia.
Adam Martinac, a Postdoc and corresponding author of the study, highlighted yawning’s enigmatic function, stating, “Yawning remains very mysterious, even though it’s a primordial process that has been preserved throughout evolution.”
The study suggests that yawning might help regulate brain temperature. During a yawn, cooler arterial blood flows into the skull, which could aid in thermoregulation.
Researchers found that each person has a unique yawn signature. This signature is identifiable by the complex movement of the tongue during the action, offering a potential new area of study.
The investigation involved a small group of 22 participants, and the findings were published in Respiratory Physiology & Neurobiology. This research could pave the way for further studies on the physiological role of yawning.
Despite being a common human action, yawning remains poorly understood. Crocodiles and potentially dinosaurs also yawned, suggesting a fundamental physiological role beyond social cues like boredom.
Human fetuses have been observed to yawn during early development, indicating its deep evolutionary roots. However, the specific reasons for yawning continue to elude scientists.
The researchers are hopeful that their findings will prompt more investigations into how yawning might affect brain health and its implications for diseases like dementia. More extensive studies could further explore the relationship between yawning and fluid dynamics in the brain.
According to the research, the act of yawning may influence cerebrospinal fluid flow, which is crucial since this fluid cushions and protects the brain and spinal cord from injury. It also helps carry nutrients in and waste products out, underscoring its importance in brain health.
The study was conducted in collaboration with Neuroscience Research Australia (NeuRA), adding significant expertise to the research team. This partnership aims to delve deeper into the physiological functions of yawning.
