Simple Spit Test Could Diagnose Concussions

by Asher Jones

As many as 3.8 million people sustain sports- and recreation-related concussions each year in the US, but diagnoses of these brain injuries remain challenging. In a study published this week in the British Journal of Sports Medicine, researchers describe a saliva-based test that accurately detected concussions in male rugby players.

“What’s exciting about this is we not only found a very accurate way of identifying brain trauma, but also we found it in saliva, which is not invasive,” Antonio Belli, a trauma neurosurgery researcher at the University of Birmingham in the UK and a coauthor of the study, tells The Washington Post. “Everybody, including myself, has been looking at blood for many years. We’ve never really seen anything so exciting for mild traumatic brain injury.”

The test measures expression levels of 14 small noncoding RNAs in saliva, including microRNAs. “MicroRNAs are messages the cells transmit in response to an event, like a brain injury,” Belli tells The Guardian.“The place where you find microRNAs most abundantly is saliva. Salivary glands are connected directly to the brain by nerves. We’re seeing this response within minutes of injury.”

The researchers compared saliva samples in male rugby players that experienced head injuries, uninjured players, and those with injuries to another part of the body. More than 1,000 people participated in the study. On the basis of these RNA saliva biomarkers, they detected concussions with 94 percent accuracy, the Post reports.

Concussion diagnoses are often made based on symptoms such as behavior or, in hospital settings, with brain imaging. “The diagnosis of concussions is really based on clinical findings. A lot of that is based on what a person reports,” William Barr, the director of neuropsychology at New York University who wasn’t involved with the research, tells the Post. “What we’ve always been looking for is: Is there something objective? Because, in a lot of cases, they’ll deny [feeling symptoms]. That’s what this really adds.” 

The saliva-based test described in the study relies on PCR and must be sent to a lab for analysis. But, according to The Guardian, the researchers are in the process of developing an over-the-counter version that could provide instant results to injured athletes, victims of traffic accidents, soldiers, and others who experience head injuries.

There is currently an FDA-approved blood test for concussion that measures the abundance of two proteins. Penn State researchers have also developed a test that measures saliva noncoding RNAs as biomarkers of concussion. According to Fox43, these researchers are also planning to develop a handheld tool that could deliver results within 30 minutes. 

Notably, the UK-based study only tested male rugby players. Research suggests that there are gender- and sex-related differences in concussions, meaning that further study would be needed before the test could be applied to women.

New Smartphone App Could Transform Concussion Management of Military Personnel

Researchers from the Department of Biomedical Engineering, led by Jay Alberts, PhD, have developed a mobile application that can accurately quantify cognitive and motor functions, which may be used in the management of mild traumatic brain injury (mTBI, or concussion). In an article in Military Medicine, the researchers report that the application has the potential to be extremely helpful in assessing performance in military personnel, who may experience mTBI in the field.

Up to 20 percent of people who have an mTBI have symptoms for months after the incident, including trouble with balancing and difficulty with certain aspects of cognition, such as attention and processing information. These effects can be especially detrimental to military personnel, who must often utilize cognitive and motor skills (dual-task) simultaneously under high-pressure situations, such as on a combat field.

The application was born of the lab’s desire to improve diagnostic ability and management of mTBI. “We wanted to address what we felt was a fundamental gap—the lack of an objective and rapid assessment of motor and cognitive performance under dual-task conditions,” said Amanda Penko, PhD, research associate in the Alberts lab and first author on the study.

Single- and dual-task testing

In the study, 50 healthy civilians took part in both single- and dual-task tests that involved balance and cognitive tasks. Tests were performed in a variety of positions—standing, sitting, and with eyes open and closed. Dual tasks while standing included discriminating between words and colors; even and odd numbers; and male and female voices. Balance tasks involved static (non-moving) standing trials with eyes open and closed.

Dr. Penko noted that maintaining balance depends in large part on the visual system—in other words, it’s easier to maintain balance when your eyes are open than when they are closed, because vision provides information on the world around us.

A new day for mTBI management?

The mobile device application was able to successfully quantify cognitive and balance performance under dual-task conditions. “What’s exciting about this application is that because it is so portable, using only a mobile device, it can be used in a variety of environments, such as a military field or in a clinic,” said Dr. Penko. “It doesn’t require any special equipment, so it’s very convenient and cost-effective.”

She added that the results of the study and the application may provide information that can be used in clinical decision-making, which can lead to a higher quality of care for those with mTBI. For instance, if a patient is having difficulty under dual-task conditions, he or she could be referred for rehabilitation to improve performance. The application could thus be useful for other people at high risk of concussion and trauma, such as football players.

“This opens up so many possibilities for standardization in the treatment of mTBI,” Dr. Penko said. “The ability to assess motor and cognitive function simultaneously, with the help of a consumer electronics device, could really transform the way we manage mTBI.”

This study was supported by the Department of Defense.

Head injuries may worsen cognitive decline decades later

People who experienced head injuries in their 50s or younger score lower than expected on cognitive tests at age 70, according to a study led by UCL researchers.

Head injuries did not appear to contribute to brain damage characteristic of Alzheimer’s disease, but might make people more vulnerable to dementia symptoms, according to the findings published in Annals of Clinical and Translational Neurology.

Lead author Dr. Sarah-Naomi James (MRC Unit for Lifelong Health and Ageing at UCL) said: “Here we found compelling evidence that head injuries in early or mid-life can have a small but significant impact on brain health and thinking skills in the long term. It might be that a head injury makes the brain more vulnerable to, or accelerates, the normal brain ageing process.”

The study involved 502 participants of the UK’s longest-running cohort study, the MRC National Survey of Health and Development Cohort, which has been following participants since their birth in the same week in 1946.

At age 53, they were asked ‘Have you ever been knocked unconscious?’ to assess whether they had ever suffered a substantial head injury; 21% of their sample had answered yes to this question. And then around age 70 (69-71), the study participants underwent brain scans (PET/MRI), and they took a suite of cognitive tests.

The participants had all completed standardised cognitive tests at age eight, so the researchers were able to compare their results at age 70 with expected results based on their childhood cognition and other factors such as educational attainment and socioeconomic status.

The researchers found that 70-year-olds who had experienced a serious head injury more than 15 years earlier performed slightly worse than expected on cognitive tests for attention and quick thinking (a difference of two points, scoring 46 versus 48 on a 93-point scale). They also had smaller brain volumes (by 1%) and differences in brain microstructural integrity, in line with evidence from previous studies, which may explain the subtle cognitive differences.

The researchers did not find any differences in levels of the amyloid protein, implicated in Alzheimer’s disease, or other signs of Alzheimer’s-related damage.

Dr. James said: “It looks like head injuries can make our brains more vulnerable to the normal effects of ageing. We have not found evidence that a head injury would cause dementia, but it could exacerbate or accelerate some dementia symptoms.”

Joint senior author Professor Jonathan Schott (UCL Dementia Research Centre, UCL Queen Square Institute of Neurology) said: “This adds to a growing body of evidence linking head injury with brain health many years later, with yet more reasons to protect the brain from injury wherever possible.”

The researchers did not have data on the frequency, severity or cause of the head injuries, to see if long-term impacts might have been even greater for certain people. The academics are continuing their research with this cohort to see if neurodegeneration or cognitive decline continues in late life among those with past head injuries.

Joint senior author Professor Nick Fox (UCL Dementia Research Centre and UK Dementia Research Institute at UCL) added: “Serious head injury can have immediate devastating effects, but what is becoming increasingly clear is that less severe but repeated head injuries—such as those sustained in contact sports—can have an effect on brain health many years later.

“Our study shows that, even in the general population, a head injury sufficient to cause a loss of consciousness can subtly affect cognition in later life. It has never been more clear that we need to do all we can to protect our brains from injury throughout our lives.”

The study was funded by Alzheimer’s Research UK, the Medical Research Council (MRC) Dementias Platform UK, the Wolfson Foundation and The Drake Foundation, and involved researchers at UCL, London School of Hygiene and Tropical Medicine, King’s College London, University of Gothenburg and the UK Dementia Research Institute.

Lauren Pulling, CEO of The Drake Foundation, which funds research on head impacts in sport, said: “These new findings add to the growing evidence base showing that head impacts can have tangible, long-term effects on the brain. With this in mind, and in addition to further research, it is essential that sport’s governing bodies take note and use a common-sense approach to universally minimise players’ risk of head injury, right through from grassroots to elite levels.”

Dr. Susan Kohlhaas, Director of Research at Alzheimer’s Research UK, said: “With millions of people around the world experiencing head injuries every year, reducing the risk of sustaining these injuries should be an important public health goal. Looking for brain shrinkage and other signs of damage soon after a head injury, are important steps towards understanding how brain injury is related to brain health and long-term thinking and memory problems.

“As the UK’s leading dementia research charity we are pleased to have funded this research and these findings add to our understanding of the factors that affect the health of the brain. While head injuries are usually impossible to predict or avoid, there are steps that we can all take to help keep our brains healthy as we age.

“That’s why Alzheimer’s Research UK has launched the campaign to engage people with this important aspect of their health and to make the public more aware of the things they can do to support their brain health.”

Structure and dynamics of key receptor in migraine pain determined, paving way for better treatment options

The trigeminal nerve is the fifth cranial nerve and is responsible for transmitting sensations from the face, brain lining (meninges), eyes, sinuses, TMJs, ears, salivary glands, mouth, nasal cavity and teeth to the brain. It is composed of three branches; the ophthalmic, maxillary, and mandibular. It is also the nerve that controls the muscles used for chewing. Credit:
CGRP receptor signaling complex structure. Visualization provided by Patrick M. Sexton, PhD.

A research team with members from Monash University, the ARC Centre for Cryo-electron Microscopy of Membrane Proteins, the University of Tokyo and the University of Otago have determined the shape and kinetics of an important cell surface (membrane) receptor called calcitonin gene-related peptide (CGRP), which has long been implicated in migraine. The work has been published in the journal Science.

Migraine is more than a simple headache; more than 3 million migraineurs—more than 60% of whom are women—have at least one attack per year. A smaller subset experience chronic migraine, defined by migraine pain that occurs 15 days or more per month, for three or months in a row. While sufferers experience many different symptoms of varying intensity—usually nausea, dizziness, sensitivity to light and sound, and intense pain on one or both sides of the head—the physiological process of migraine onset and pain is different from other types of headache, such as muscle tension or sinus pain. While migraine was long believed to be a neurovascular disorder that involved dilation of vessels in the skull, face and cerebral membrane, research has excluded vasodilation as a factor in this type of painMore recent work has identified increased CGRP in the trigeminal sensory nervous pain pathway that results in headache.

“We determined the atomic structure of an important cell surface (membrane) receptor that is implicated in migraine,” says Dr. Radostin Danev of the Graduate School of Medicine, University of Tokyo. “In this initial study, we determined the structure of the receptor alone and in combination with its natural target molecule (CGRP). This gives us a clear understanding of how the receptor works during its normal function in the body.”

Future studies will expand the investigations towards potential drug targets. “There are already several migraine drugs that target the receptor, but structural knowledge is essential for understanding the pharmacology and for future therapy developments” that will “help us understand the pathology mechanisms of chronic diseases and to aid in the development of more effective and accessible treatments,” says Dr. Danev.

Identifying the structure of CGRP “is one of the first molecular revelations of the initiating events that are associated with migraine pain,” explains Dr. Patrick M. Sexton, Professor of Pharmacology at Monash University and a corresponding author of the paper. “The approach we used to do this (cryo-EM) is similar to the approach used to support vaccine and drug development for COVID.”

While this research and all research into COVID-19 is recent, cryogenic electron microscopy (cryo-EM) has been in use since the 1970s. Advances in the past decade have improved detector technology and computational imaging, allowing cryo-EM to reveal biomolecular structures at near-atomic resolution. Dr. Danev is excited for the future of cryo-EM research: “This is the first successful high-resolution cryo-EM study of an isolated G protein-coupled receptor in inactive and pre-activation states, without the presence of a G protein. It showcases the ever-expanding capabilities of cryo-EM for the structure determination of small membrane proteins.” And while the team are thrilled with the results of their work, the real benefit is forthcoming, Dr. Danev says. “This work paves the way towards further studies of inactive GPCRs, which until now have been a prerogative of X-ray crystallography.”

So where do we go now that we have this understanding of CGRP’s structure and the ability to investigate it and others? “The new structures and understanding of the motions of the receptors could be used to design better ways of activating this receptor,” explains Dr. Sexton. “While the work unravels a key event in migraine, we already have treatments recently approved that effectively target the receptor we studied. However, sometimes we will actually want to increase activation of the receptor to treat other diseases.”

More information: Tracy M. Josephs et al. Structure and dynamics of the CGRP receptor in apo and peptide-bound forms, Science (2021). DOI: 10.1126/science.abf7258

Fast-tracking drug development for neurodegenerative disorders

The three-dimensional structure of the SARM1 protein determined by cryo-electron microscopy. Credit: Jeff Nanson.

A Griffith University-led research team has discovered how a therapeutic target common among debilitating neurodegenerative disorders is activated, which could help accelerate drug development.

In a study published in the journal Neuron, the researchers from Griffith University’s Institute for Glycomics, the University of Queensland and Washington University, analyzed the structure and function of a protein called SARM1, which is involved in the destruction of nerve fibers. They found that the protein is a sensor that responds to the levels of specific molecules derived from metabolism.

“SARM1 is a potential therapeutic target for many neurodegenerative diseases,”‘ said lead author and Institute for Glycomics researcher, Dr. Thomas Ve.

“When nerve fibers are damaged, whether by injury, disease or as a side effect of certain drugs, SARM1 is called into action which sets off a series of events in the cell that trigger them to self-destruct.

“This destruction likely plays an important role in multiple neurodegenerative conditions, including peripheral neuropathy, Parkinson’s disease, amyotrophic lateral sclerosis (ALS), traumatic brain injury and glaucoma.”

Dr. Ve and joint first author on the paper, Dr. Yun Shi used NMR spectroscopy, a biophysical tool to analyze interactions between proteins and small molecules, to demonstrate that two important metabolites in nerve cells compete for binding to the SARM1 protein, and the ratio of these two metabolites determines whether SARM1 becomes activated.

Dr. Ve and collaborators also used structural biology tools—Cryo-electron Microscopy and X-ray Crystallography—to determine three-dimensional structures of the SARM1 protein which enabled them to pinpoint exactly where these two metabolites bind to SARM1 and how they regulate SARM1 activation.

Dr. Ve, also an Australian Research Council Future Fellow and NHMRC Investigator, said the new structural information about SARM1 had the potential to accelerate the development of drugs that target neurodegenerative diseases.

“We are very excited by these findings as they greatly advance our understanding of how SARM1 is activated,” he said.

“It provides clues as to how one might block activation of this protein using structure-guided approaches to prevent nerve fiber loss in neurodegenerative diseases.”

Professor Mark von Itzstein AO, Director of the Institute for Glycomics, welcomed this important breakthrough. “New strategies towards solving neurodegenerative diseases have become increasingly important due to the enormous impact on the quality of life of those that suffer with these conditions.”

More information: Matthew D. Figley et al. SARM1 is a metabolic sensor activated by an increased NMN/NAD+ ratio to trigger axon degeneration, Neuron (2021). DOI: 10.1016/j.neuron.2021.02.009

Renaissance-era letter sealed for centuries just virtually unfolded and read for the first time

Computer-generated unfolding animation of sealed letter DB-1538. (Image credit: Courtesy of the Unlocking History Research Group archive)
A seventeenth-century trunk that was bequeathed to the Dutch postal museum in the Hague contained thousands of letters that were sent from all over Europe and were never delivered. (Image credit: Courtesy of the Unlocking History Research Group archive)

“Virtual unfolding” enabled researchers to read the contents of sealed letterpackets from 17th-century Europe without physically opening them. (Image credit: Courtesy of the Unlocking History Research Group archive)

By Mindy Weisberger

More than 600 years ago, someone intricately folded, sealed and posted a letter that was never delivered. Now, scientists have digitally “unfolded” this and other similarly locked letters found in a 17th-century trunk in The Hague, using X-rays

For centuries prior to the invention of sealed envelopes, sensitive correspondence was protected from prying eyes through complex folding techniques called “letterlocking,” which transformed a letter into its own secure envelope. However, locked letters that survive to the present are fragile and can be opened physically only by slicing them to pieces. 

The new X-ray method offers researchers a non-invasive alternative, maintaining a letterpacket’s original folded shape. For the first time, scientists applied this method to “locked” letters from the Renaissance period, kept in a trunk that had been in the collection of the Dutch postal museum in The Hague, The Netherlands, since 1926. 

The trunk’s contents include more than 3,100 undelivered letters, of which 577 were unopened and letterlocked. Known as the Brienne Collection, the letters were written in Dutch, English, French, Italian, Latin and Spanish. For unknown reasons, once the missives reached The Hague they were never delivered to their intended recipients, and were instead kept by a postmaster named Simon de Brienne, Live Science previously reported

Locked letters used different mechanisms to stay securely closed, including folds and rolls; slits and holes; tucks and adhesives; and a variety of cleverly constructed locks, according to a study published online March 2 in the journal Nature Communications.

To penetrate the layers of folded paper, the study authors used an X‐ray microtomography scanner engineered in the dental research labs at Queen Mary University of London (QMU). Researchers designed the scanner to be exceptionally sensitive so that it could map the mineral content of teeth, “which is invaluable in dental research,” study co-author Graham Davis, a QMU professor of 3D X-ray imaging, said in a statement

“But this high sensitivity has also made it possible to resolve certain types of ink in paper and parchment,” Davis added.

“The rest of the team were then able to take our scan images and turn them into letters they could open virtually and read for the first time in over 300 years,” study co-author David Mills, an X-ray microtomography facilities manager at QMU, said in the statement.

From the scans, the team built 3D digital reconstructions of the letters, and then created a computational algorithm that deciphered the sophisticated folding techniques, crease by crease, opening the letters virtually “while preserving letterlocking evidence,” according to the study. 

The scientists digitally opened four letters using this groundbreaking method, deciphering the contents of one letter, DB-1627. Penned on July 31, 1697, it was written by a man named Jacques Sennacques to his cousin Pierre Le Pers, who lived in The Hague. Sennacques, a legal professional in Lille, France, requested an official death certificate for a relative named Daniel Le Pers, “perhaps due to a question of inheritance,” the scientists wrote.

“His request issued, Sennacques then spends the rest of the letter asking for news of the family and commending his cousin to the graces of God,” the authors wrote. “We do not know exactly why Le Pers did not receive Sennacques’ letter, but given the itinerancy of merchants, it is likely that Le Pers had moved on.” Tens of thousands of such sealed documents can now be unfolded and read virtually, the researchers reported.

“This algorithm takes us right into the heart of a locked letter,” the research team said in the statement. “Using virtual unfolding to read an intimate story that has never seen the light of day — and never even reached its recipient — is truly extraordinary.”

NYC woman discovers empty apartment behind bathroom mirror

By Wilson Wong

A woman in New York City went viral on TikTok Wednesday after posting a video series documenting her journey to discover a secret unoccupied apartment behind her bathroom mirror.

In the first video of her four-part saga, Samantha Hartsoe said she was trying to find the source of cold air that was blowing into her Manhattan apartment. When she discovered that the air was coming from behind her bathroom mirror, Hartsoe said she removed it from the wall.

What Hartsoe said she found was a large square-shaped hole in the wall that peered into a dark room — a scene that watchers compared to the Oscar-winning film, “Parasite” and the 1992 horror film “Candyman,” where a murderous spirit appears after victims repeatedly call his name into the mirror.

Hartsoe ultimately decided to venture into the other side of her bathroom.

“Curiosity killed the cat, curiosity is going to kill me,” Hartsoe told NBC New York. “I can’t not know what’s on the other side of my bathroom.”

The videos showed Hartsoe, clad in a face mask, headlight, and hammer, twisting her body into the hole, much to the dismay of her roommates.

“My roommates definitely thought I was going to be dead,” she said. “Every corner I would walk normal and then be like [moving her head] to check.”

On the other side of the hole was an entire apartment that appeared to be unfinished and unoccupied, the video showed. Bags of trash and an uninstalled toilet littered the floors.

After investigating both floors of the apartment, Hartsoe locked the front door to the empty apartment and returned back to her apartment through the hole in her bathroom.

“When I came back [my roommates] were excited,” she said.

More than nine million viewers have watched Hartsoe’s mysterious journey on TikTok as of Friday afternoon.

Hartsoe added she has not contacted her landlord yet, but has contacted the maintenance department to fix the hole behind her mirror.

Green tea supplements modulate facial development of children with Down syndrome

The observational study suggests that the green tea supplements only affect facial development when they are administered in the early stages of life.

A new study led by Belgian and Spanish researchers published in Scientific Reports adds evidence about the potential benefits of green tea extracts in Down syndrome. The researchers observed that the intake of green tea extracts can reduce facial dysmorphology in children with Down syndrome when taken during the first three years of life. Additional experimental research in mice confirmed the positive effects at low doses. However, they also found that high doses of the extract can disrupt facial and bone development. More research is needed to fully understand the effects of green tea extracts and therefore they should always be taken under medical supervision.

Down syndrome is caused by the presence of a third copy of chromosome 21, leading to an overexpression of the genes in this region and resulting in a number of physical and intellectual disabilities. One of the genes, DYRK1A, contributes to altering brain and bone development in people with Down syndrome. The green tea compound EGCG (epigallocatechin-3-gallate) is known to inhibit DYRK1A activity, although it also has other mechanisms of action. Previous research has shown the potential of EGCG to improve cognition in young adults with Down syndrome.

In a new study, researchers analyzed the effect of green tea supplements on facial development in Down syndrome. In the experimental part of the study, the EGCG supplements were tested in mice at different dosages. In a second part of the research, they did an observational study on children with and without Down syndrome. This work, led by the Centre for Genomic Regulation (CRG), European Molecular Biology Laboratory (EMBL) and University of Barcelona in Spain and KU Leuven in Belgium, is an international effort involving researchers from University of Central Florida, La Salle—University Ramon Llull, and IMIM—Hospital del Mar Medical Research Institute.

For the mouse study, carried out at KU Leuven, the researchers started the treatment before birth, while the pups were developing in the wombs of their mothers, by adding either a low or a high dose of green tea extracts to their drinking water. “The low dose treatment had a positive effect on mice that are a model of Down syndrome,” Professor Greetje Vande Velde (KU Leuven) comments, co-lead author of the study. “Sixty percent of them showed a facial shape similar to the control group.”

“The high dose treatment, however, generated very mixed results, and even disrupted normal facial development in some cases, causing additional dysmorphology. This occurred in all mice, in the model of Down syndrome as well as in the control group.”

Age-dependent effects

The observational study was set up in Spain and also included participants from North America. 287 children between 0 and 18 years participated, including children with Down syndrome who did (n = 13) or didn’t (n = 63) receive EGCG supplementation. The treated group were all self-medicated and didn’t follow a prescribed protocol.

“All participants were photographed from various angles to create a 3-D model of their faces,” explains Neus Martínez-Abadías, professor at the University of Barcelona and co-lead author of the study. “We use 21 facial landmarks, and the distances between them, to compare the faces of the participants. In the youngest group between 0 and 3 years, we observed that 57 percent of the linear distances are significantly different when you compare the faces of children with Down syndrome that never received the treatment to those of children that do not have Down syndrome. For babies and toddlers who did receive EGCG treatment, this difference was much smaller, only 25 percent. After green tea supplementation, the facial dysmorphology decreases and the children with or without Down syndrome look more alike.”

“We didn’t identify a similar effect in the adolescent group. Even when treated with green tea extracts, children with Down syndrome still show a difference of more than 50 percent compared to the control group. These findings suggest that the green tea supplements only affect facial development when they are administered in the early stages of life when the face and skull are rapidly growing.”

Further research required

“Despite the potential benefits we observed, we must handle these findings with caution considering they are preliminary and based on an observational study,” Professor Vande Velde warns. “Much more research is necessary to evaluate the effects of EGCG-containing supplements, the appropriate dose and their therapeutic potential in general. We also need to take into the account possible effects on other organs and systems, not just on the development of the face. This requires first more basic research in the lab with mice, and then clinical studies with more participants and controlled use of these supplements.”

“Our findings suggest that effects of EGCG strongly depend on the dose.” Professor Martínez-Abadías concludes. “EGCG products are commercially available and they are used regularly as a general health-promoting compounds. However, it’s important to follow the European Food Safety Authority recommendations regarding the maximal intake and to always consult a physician before taking the supplements. Our research shows potential beneficial effects of facial development at low doses, but at very high doses they can produce unpredictable effects in mice. More research is needed in humans to determine the optimal dose at each age that maximizes the potential benefits.”

More information: John M. Starbuck et al, Green tea extracts containing epigallocatechin-3-gallate modulate facial development in Down syndrome, Scientific Reports (2021). DOI: 10.1038/s41598-021-83757-1

Discovery of three deep-sea sharks that glow in the dark

Researchers believe sharks probably glow for camouflage to protect from attack from beneath.

Scientists studying sharks off New Zealand have discovered that three deep-sea species glow in the dark – including one that is now the largest-known luminous vertebrate.

Bioluminescence – the production of visible light through a chemical reaction by living organisms – is a widespread phenomenon among marine life but this is the first time it has been documented and analysed in the kitefin shark, the blackbelly lanternshark, and the southern lanternshark.

The sharks were collected during a fish survey of the Chatham Rise off the east coast of New Zealand in January 2020.

The kitefin, which can grow to 180cm, is now the largest-known luminous vertebrate: what researchers referred to as a “giant luminous shark”.

The researchers, from the Université Catholique de Louvain in Belgium and the National Institute of Water and Atmospheric Research in New Zealand, said the findings had repercussions for our understanding of life in the deep sea; one of the least-studied ecosystems on the planet.

The sharks all live in what is known as the mesopelagic or “twilight” zone of the ocean, between 200 and 1,000 metres deep, beyond which sunlight does not penetrate. Seen from below, the sharks appear backlit against the bright surface of the water, leaving them exposed to potential predators without any place to hide.

Researchers suggest these three species’ glowing underbellies may help camouflage them from any threats that might strike from beneath.

In the case of the kitefin shark, which has few or no predators, it is possible that the slow-moving species uses its natural glow to illuminate the ocean floor while it searches for food, or to disguise itself while approaching its prey.

Further study would be needed to confirm either hypothesis, the researchers wrote in a paper published in the Frontiers in Marine Science journal, as well as to understand just how the species’ bioluminescence functioned – and possible implications for prey-predation relationships.

“Considering the vastness of the deep sea and the occurrence of luminous organisms in this zone, it is now more and more obvious that producing light at depth must play an important role structuring the biggest ecosystem on our planet,” the researchers wrote.

Jérôme Mallefet, lead researcher from the Marine Biology Laboratory of the Université Catholique de Louvain in Belgium, said: “The luminous pattern of the Kitefin shark was unknown and we are still very surprised by the glow on the dorsal fin. Why? For which purpose?”

The size of the territories inhabited by the sharks makes this kind of study very difficult, he said. “The two other Etmopterus sharks were also not documented, so it is the first time.”

Mallefet hopes to be back out at sea soon to continue the work, and look for more luminous species.

Custom diets are essential to mental health, new research shows

Customized diets and lifestyle changes could be key to optimizing mental health, according to new research including faculty at Binghamton University, State University of New York.

“There is increasing evidence that diet plays a major role in improving mental health, but everyone is talking about a healthy diet,” said Begdache, an assistant professor of health and wellness studies at Binghamton University and co-author of a new paper in Nutrients.

“We need to consider a spectrum of dietary and lifestyle changes based on different age groups and gender,” she said. “There is not one healthy diet that will work for everyone. There is not one fix.”

Begdache, who is also a registered dietitian, believes that mental health therapies need to consider the differences in degree of brain maturity between young (18-29 years old) and mature (30 years or older) adults, as well as the brain morphology among men and women.

She and her research team conducted an online survey to examine food intake, dietary practices, exercise and other lifestyle factors in these four subpopulations. Over a five-year period (2014-19), more than 2,600 participants completed the questionnaire after responding to social media posts advertising the survey. The team collected data at different timepoints and seasons and found important dietary and lifestyle contributors to mental distress—defined as anxiety and depression—in each of the groups.

Key findings of this study:

  • Significant dietary and lifestyle approaches to improve mental well-being among young women include daily breakfast consumption, moderate-to-high exercise frequency, low caffeine intake and abstinence from fast food.
  • Dietary and lifestyle approaches to improve mental well-being among mature women include daily exercise and breakfast consumption, as well as high intake of fruits with limited caffeine ingestion.
  • To improve mental well-being of young men, dietary and lifestyle approaches include frequent exercise, moderate dairy consumption, high meat intake, as well as low consumption of caffeine and abstinence from fast food.
  • Dietary approaches to improve mental well-being among mature men include moderate intake of nuts.

Begdache and her team split the respondents into two age groups because human brain development continues into the late 20s. For young adults of both genders, quality of diet appears to have an impact on the developing brain.

“Young adults are still forming new connections between brain cells as well as building structures; therefore, they need more energy and nutrients to do that,” Begdache said.

As a result, young adults who consume a poor-quality diet and experience nutritional deficiencies may suffer from a higher degree of mental distress.

Age is also the reason high caffeine consumption was associated with mental distress in both young men and young women.

“Caffeine is metabolized by the same enzyme that metabolizes the sex hormones testosterone and estrogen, and young adults have high levels of these hormones,” Begdache said. “When young men and women consume high levels of caffeine, it stays in their system for a long time and keeps stimulating the nervous system, which increases stress and eventually leads to anxiety.”

The team also split respondents based on biological sex, since brain morphology and connectivity differ between men and women. Put simply, the male brain is “wired” to enable perception and coordination, whereas the female brain is built to support analysis and intuition. Begdache and her team believe these differences may influence nutritional needs.

“I have found it in my multiple studies so far, that men are less likely to be affected by diet than women are,” said Begdache. “As long as they eat a slightly healthy diet they will have good mental well-being. It’s only when they consume mostly fast food that we start seeing mental distress.

“Women, on the other hand, really need to be consuming a whole spectrum of healthy food and doing exercise in order to have positive mental well-being,” she added. “These two things are important for mental well-being in women across age groups.”

According to Begdache, current recommendations for food intake are all based on physical health; there are no recommendations for mental health. She hopes that will change—and that her work will play a role in making those changes.

“I hope to see more people doing research in this area and publishing on the customization of diet based on age and gender,” she said. “I hope that one day, institutions and governments will create dietary recommendations for brain health.”

More information: Lina Begdache et al, Diet, Exercise, Lifestyle, and Mental Distress among Young and Mature Men and Women: A Repeated Cross-Sectional Study, Nutrients (2020). DOI: 10.3390/nu13010024