School of Biomedical Engineering<\/a>.<\/p>\n\u201cThere has been speculation that yawning can help clear waste from the brain, but so far there has not been solid proof.<\/p>\n
\u201cOur research suggests that yawning can play a role in cleaning brain fluid, which would most likely happen close to bedtime.\u201d<\/p>\n
This finding could be important for further studies into neurodegenerative diseases such as Alzheimer’s, Parkinson\u2019s and dementia\u00a0\u2014 all of which have been potentially linked to\u00a0the build-up of waste products in and around the brain that can be a result of impaired CSF flows.<\/p>\n
\u201cWe think there’s something here really worth investigating further. Those neurodegenerative diseases are associated with an accumulation of waste and the older you get the more waste there can be,\u201d said Martinac.<\/p>\n
\u201cWe don\u2019t know how strong the link is related to how CSF is cleared, but in the last 10 years there have already been a lot of investigations into that area, and this can be another element.\u201d<\/p>\n
One of the key observations was that CSF flow when people yawned was the opposite of what happened when they simply took a deep breath.<\/p>\n
The team showed volunteers videos of people, and even animals, yawning in order to trigger so-called contagious yawns.<\/p>\n
MRI scans were taken at the level of their C3 vertebra, a crossroads in the upper neck where blood and CSF pass as they travel to and from the brain. The scans of the subjects contagiously yawning were then compared to those when they simply took a deep breath as if pretending to yawn.<\/p>\n
In normal breathing the venous blood, that which has delivered oxygen, drains out of the skull and back towards the heart. The CSF flows in the opposite direction during that physiological process.<\/p>\n
Even when the volunteers were pretending to yawn, the venous blood flowed out and CSF flowed into the skull.<\/p>\n
Only when they were really yawning, via those contagious yawns, did venous blood and CSF flow out of the skull together.<\/p>\n
Thermoregulation<\/b><\/p>\n
The UNSW research team also say the evidence suggests yawning is a way for the body to regulate the temperature in and around the brain.<\/p>\n
\u201cIn humans, the brain tissue can be up to one degree Celsius warmer than the rest of the body, and venous blood leaving the brain is typically about 0.2-0.3 degrees warmer than the arterial blood entering it,\u201d said Martinac.<\/p>\n
\u201cSo when someone yawns we can now see an increase in the cooler arterial blood flow into the skull, compensating for the coupled outflow of CSF and venous blood, and therefore we can surmise there may be a thermoregulatory process happening there.\u00a0<\/p>\n
\u201cWe could speculate that perhaps yawning is a way that the brain helps to cool itself down, but again we would need to do more research to state that with certainty.<\/p>\n
\u201cWe do know that a hot brain is not a good thing because there is a risk of cell damage, seizures and cerebral swelling. And there is actually a very narrow band temperature-wise where the brain is steady and balanced, what is known as homeostasis.<\/p>\n
\u201cThat\u2019s likely the reason why there are so many mechanisms \u2013 such as blood flow, and sweating \u2013 that help regulate temperatures in the brain.<\/p>\n
\u201cWe don\u2019t fully know what the level of contribution yawning may play in that, but this research opens up some interesting avenues for further investigation in that area as well.\u201d<\/p>\n
The researchers\u00a0also say they have identified for the first time that people appear to have a unique signature to their individual yawn which can be identified by the complex way their tongue moves during the action.<\/p>\n
\u201cAnother interesting thing we found is that each person yawns in a unique way\u00a0\u2014 so the tongue motion during the yawn is different between people, but very consistent for each person,” Martinac said.<\/p>\n
“And it’s not a simple motion. It’s a very complex movement of the tongue during a yawn.<\/p>\n
“It’s almost like a fingerprint, so you could possibly identify someone just based on how they yawn.”<\/p>\n
This press release has also been published on VRITIMES<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"A new imaging study from UNSW Sydney suggests yawning may help move\u00a0important fluids out of<\/p>\n","protected":false},"author":1,"featured_media":43885,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11],"tags":[],"class_list":["post-43884","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-australia"],"_links":{"self":[{"href":"https:\/\/seareporthub.com\/index.php?rest_route=\/wp\/v2\/posts\/43884","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/seareporthub.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/seareporthub.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/seareporthub.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/seareporthub.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=43884"}],"version-history":[{"count":0,"href":"https:\/\/seareporthub.com\/index.php?rest_route=\/wp\/v2\/posts\/43884\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/seareporthub.com\/index.php?rest_route=\/wp\/v2\/media\/43885"}],"wp:attachment":[{"href":"https:\/\/seareporthub.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=43884"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/seareporthub.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=43884"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/seareporthub.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=43884"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}