Stress, anxiety, and depression are emotions we all feel at some point in our lives, some people to a greater degree than others. Part of the human experience, right?
“It may seem odd that my research focuses on the gut if I’m interested in the brain,” says John Cryan, a researcher at the APC Microbiome Institute at University College Cork in Ireland. “But when we think of how we express emotion in language, through sayings like ‘butterflies in your tummy’ and ‘gut feeling,’ it isn’t surprising that they’re connected.”
In a recent study, Cryan and his colleagues reported a link between the microbiome and fear. By examining mice with and without gut bacteria, they discovered that the germ-free mice had blunted fear responses (Mol Psychiatr, doi:10.1038/mp.2017.100, 2017). Their findings may pave the way for the development of novel treatments for anxiety-related illnesses, including posttraumatic stress disorder.
Researchers at Kyushu University in Japan were the first to show, in 2004, that bacteria in the gut can influence stress responses, prompting many subsequent investigations. Yet despite mounting research, scientists remain uncertain about exactly how the gut microbiome affects the brain. While some bacteria influence the brain through the vagus nerve, other strains seem to use different pathways. It is known, however, that the population of the gut microbiome begins in early life, and recent research suggests that disruptions to its normal development may influence future physical and mental health (Nat Commun, 6:7735, 2015).
Researchers are finding that this gut-brain connection could have clinical implications, as influencing the gut microbiome through diet may serve to ameliorate some psychiatric disorders. Together with University College Cork colleague Ted Dinan, Cryan coined the term “psychobiotics” in 2013 to describe live organisms that, when ingested, produce health benefits in patients with psychiatric illness. These include foods containing probiotics, live strains of gut-friendly bacteria.
While there are many rodent studies linking probiotics and mental health, UCLA biologist Emeran Mayer and his colleagues were the first to test them in humans, using functional magnetic resonance imaging (fMRI) scans to assess the results. After administering probiotic yogurt to a group of healthy women twice a day for four weeks, the researchers found that the women had a reduced brain response to negative images (Gastroenterology, 144:1394-401, 2013).
“We reanalysed the data several times and convinced ourselves that it’s real,” Mayer says. “You can almost say it was a career-changer for me.”
Having conducted this study on healthy participants, Mayer is reluctant to conclude that probiotics can cure mental illnesses such as anxiety. “It’s a complex emotion, not just a reflex behavior like in the mouse,” he says. However, Mayer says he’s very supportive of the potential of prebiotics—fiber-rich foods that promote the growth of beneficial bacteria in the gut.
Researchers at Deakin University in Australia recently trialed a Mediterranean-style diet, which is predominately plant-based and fiber-rich, in a group of adults with major depression. They found that one-third of the participants reported a significant improvement in symptoms after 12 weeks on the diet (BMC Medicine, 15:23, 2017). One of them was Sarah Keeble from Melbourne. “I’ve suffered from depression for 17 years. At the start of this study, I was right at the bottom of the barrel,” she recalls. “After a few weeks, that sinking feeling slowly lifted, and my motivation and enthusiasm improved.”
Just as activity in the gut seems to affect the brain, mental stress can lead to intestinal problems. Scientists have demonstrated this in research on irritable bowel syndrome. For example, a study by Mayer and colleagues linked early-life emotional trauma to an increased risk of developing the bowel disorder (Clin Gastroenterol Hepatol, 10:385-90, 2012).
As data on the brain-gut axis accumulates, many scientists are taking notice. Trinity College Dublin researcher Shane O’Mara says that there is “great potential” in this area, but cautions that it’s too early to say whether targeting the microbiome will play a role in psychiatric treatment. University of Manitoba gastroenterologist Charles Bernstein also feels the research is promising but believes we are “far from manipulating the microbiome to treat mental health disorders.”
Those spearheading this research are equally aware of the need for more studies, particularly in human subjects, but they are hopeful that change lies ahead. “I’m almost certain that in several years, diet will be considered one branch of therapy for many mental illnesses, alongside medication and psychiatric treatments,” says Mayer.
“People with severe mental illness will still need something very strong, but this is a useful adjunctive,” agrees Cryan. “I think when we go to our GP in future, we will not only have blood tests, we will have the microbiome tested.”
“Within five years, I hope to see more clinical trials that demonstrate the efficacy of prebiotics and probiotics on mental health disorders,” says University of Chicago microbial ecologist Jack Gilbert. “There needs to be a revolution in how we deal with mental illness in our society.”
(First published in The Scientist magazine September 2017. Also available online at: http://www.the-scientist.com/?articles.view/articleNo/50146/title/How-Microbes-May-Influence-Our-Behavior/)
A computer model estimates that gene-drive technology could wipe out populations of an invasive mammal on islands.
In a study published August 9 in the Proceedings of the Royal Society B, researchers at the University of Adelaide have provided modeling evidence that gene drives could indeed be an effective means to wipe out entire populations of invasive vertebrates on islands.
“The most obvious potential advantage to using gene-drive technology for this purpose is species specificity,” says Luke Alphey, a genetic pest management expert at the Pirbright Institute in the U.K. and a cofounder of Oxitec, which is commercializing other genetic-modification methods to control insects. “Genetic approaches are transmitted through mating, so the direct effect is only on the target species.”
“That aspect alone is phenomenally powerful if we are talking about working in an ecologically fragile environment,” notes Alphey, who was not involved in the study. He says the current approach for managing invasive species consists predominantly of “harmful mass poisoning.”
In this recent study, the scientists chose to test gene-drive strategies on a simulated island population of 50,000 mice that they constructed in silico. Invasive rodents are likely responsible for the greatest number of extinctions and ecosystem changes on islands, according to a 2006 study. The house mouse (Mus musculus) in particular has been shown to have a devastating effect on seabird colonies in places such as Gough Island in the South Atlantic and New Zealand’s Antipodes Islands.
“We also focused on islands because in the long term . . . if this technology is deemed a good idea and acceptable by society, islands will be the first place it is carried out as it is easier to control,” explains coauthor Paul Thomas. “There’s a long way to go before we think about using it, but we wanted to conduct this study to see if it could be a possibility.”
Using a mathematical model, the scientists tested four CRISPR-based gene-drive strategies that could be readily developed based on what is within the current literature. The “heterozygotic XX sterility” strategy, also known as the “daughterless strategy,” involves using the gene drive to spread a male sex-determining gene so that all carriers develop as males regardless of their sex chromosomes. As a result, there will be a deficiency of females and the population will eventually crash.
“Heterozygotic XX sex reversal” is a similar technique, but contains additional genetic cargo that enables XX males to transmit the gene drive. “Homozygotic XX sterility” achieves population suppression through the infertility of homozygous females. The final strategy, “homozygotic embryonic non-viability,” causes embryonic fatality through gene mutation. All of these strategies were based on the basic CRISPR-Cas9 system using a single guide RNA.
The heterozygotic XX sterility strategy failed to present itself as a viable method, the researchers found, as carrier XX males are infertile and therefore unable to pass on the gene drive. The paper notes that this method would only prove effective on the basis of a continuous release of gene drives into a population, a process that would be costly and time-consuming.
The remaining three strategies proved capable of causing rapid population decline to the point of elimination. The researchers conclude that a single introduction of just 100 mice carrying one of these gene drives could destroy an island mouse population of 50,000 individuals within four to five years.
The researchers acknowledge that, for all of these strategies, the potential for the formation of resistant genes poses a problem, as has been observed in laboratory studies of mosquito gene drives. However, by conducting further tests that involved targeting several different DNA sequences with more than one guide RNA, they found that the possibility of this resistance is reduced.
Michael Wade, who studies population genetics and mating at Indiana University, is not convinced that this solution to resistance comes without consequence. He says that by using multiple guide RNAs as the authors suggest, one could increase the risk of targeting the genome at unintended sites, which may lead to other problems.
“Release of this type of construct raises the risk of reducing the target specificity of CRISPR-Cas9 and increasing the possibility of it jumping to a different species, possibly an endemic relative of the invader species targeted for eradication,” he writes in an email to The Scientist.
Concerns have been raised by members of National Academies of Sciences, Engineering, and Medicine in a consensus study report about the potential consequences of using gene drives for species eradication, including the unintentional spread to other populations, unpredictable negative effects on the ecosystem, and ethical implications. Thomas and his colleagues are “very conscious” of these worries, he says.
“I think this method definitely has potential but we do need to do more studies, have the conversation around whether it is safe to use, and see if the benefits outweigh the risks. We are keen to engage with all members of the community,” he says. His team has now begun conducting a mouse-based gene-drive experiment in the laboratory.
T.A.A. Prowse et al., “Dodging silver bullets: good CRISPR gene-drive design is critical for eradicating exotic vertebrates,” Proc Royal Soc B, doi:10.1098/rspb.2017.0799, 2017.
(First published on The Scientist online on August 28 2017. Available online at: http://www.the-scientist.com/?articles.view/articleNo/50180/title/Driving-Down-Pests/)
What should you do if a jellyfish stings you? Scientists have found that applying vinegar is the best solution, and that popular remedies including urine, lemon juice, and shaving foam could make the situation worse.
A recent study in Toxins, which investigated the efficacy of various remedies for stings from the Portuguese man o’ war (Physalia physalis) concludes that rinsing with vinegar before applying heat is the most effective treatment. The commonly recommended treatment of seawater and ice was found to cause more harm than good.
Dr Tom Doyle, a biologist at NUI Galway and co-author of the paper, conducted research on both the Atlantic and Pacific man o’ war. He said the findings represented a complete U-turn.
“For me it was certainly surprising as we have been recommending seawater and ice for the last 10 years,” he said. “But that’s the nature of science; we have to hold up our hands and say we were wrong. We went back to basics and tested different methods. There’s no doubt about our findings. We are absolutely 100% certain that vinegar does the trick.”
The scientists tested various solutions on sheep and human blood cells suspended in agar. The method of scraping away tentacles was found to increase pressure on the affected area, causing the stinging capsules to fire more venom into the victim. However, applying vinegar was shown to prevent further venom release, allowing the tentacles to be safely removed. Immersing the area in 45C water or applying a heatpack resulted in fewer red blood cells being killed.
In contrast, rinsing with seawater was found to worsen stings by spreading venom capsules further, while cold packs caused them to fire more venom. The infamous urine theory – popularised by an episode of Friends – was also found to aggravate stings. Baking soda, shaving cream, soap, lemon juice, alcohol and cola yielded similar results.
Although vinegar is used for many other jellyfish stings, the man o’ war has long been considered an exception, with many guidelines warning against its use. While it’s true that the man o’ war is different – they are technically a siphonophore and not a jellyfish – the scientists behind this research are now arguing that all stings be treated equally.
Biologist and jellyfish expert Dr Lisa Gershwin agrees that treatment with vinegar works, but expressed concern about the hot water recommendation.
“Hot water does take away the pain but this is a neurological process; it has nothing to do with denaturing the venom,” she said. “Fresh water activates discharge and by applying heat, you are dilating the capillaries and allowing venom to go further into the body.”
The study was prompted by an influx of man o’ war on European coasts last summer and built upon the findings of a study on box jellyfish conducted by the University of Hawaii at Mānoa. The researchers will now turn their attention to the lion’s mane jellyfish to determine if the same conclusions apply.
(First published in The Guardian UK. Available online at: https://www.theguardian.com/environment/2017/may/09/vinegar-best-antidote-jellyfish-stings-urine-lemon-juice-make-worse-study)
Saving the Spanish imperial eagle was never going to be easy. This enormous bird, which once dominated the skies above Spain, Portugal, and northern Morocco, saw its numbers drop to just 380 breeding pairs in 2014, thanks to habitat loss, poaching, poisoning from farmers and hunters, and electrocution from power lines. Now, a new study highlights a potential way of restoring eagle populations to their former glory: dropping them into long-abandoned habitat.
One common approach for bringing threatened species back from the brink is to reintroduce them to the places they were last known to live. For example, the sea eagle in Scotland—which was hunted to extinction on the Isle of Skye in 1916—was successfully reintroduced in 1975 to Rùm Island near its last known breeding ground. But not all such efforts bear fruit: When scientists tried to release the same bird to its former range in western Ireland in 2007, the newcomers fell victim to the same poisoning that had done them in 107 years earlier.
“The tendency is to think that the last place that an animal was present is the best place for the species, but this isn’t always the case,” says Virginia Morandini, a biologist with the Spanish National Research Council’s Doñana Biological Station near Seville.
So Morandini and her colleagues teamed up with conservation biologist Miguel Ferrer of the Migres Foundation at Doñana to try a different approach. Along with the Andalusian government’s Spanish Imperial Eagle Action Plan, they introduced imperial eagles into a territory they last inhabited some 50 years ago, far from established populations. Their method had some strong theoretical underpinnings because relict populations that have been pushed into small, low-quality habitats—often the “last known address” of threatened species—are thought to have relatively low breeding rates.
From 2002 to 2015, the Doñana team monitored 87 eagles that had been released in the south of Cádiz province of Spain, some 85 kilometers from the nearest established eagles. Meanwhile, the researchers monitored a naturally occurring population of eagles in south-central Spain. When scientists analyzed the breeding success of the two groups—a proxy for how well the eagles might survive over the long run—they found that the relocated population produced nearly twice as many chicks, they reported last month in Ecology and Evolution. Morandini attributes their success to the ready availability of prey and breeding partners, as well as efforts to reduce threats from hunters and exposed power lines.
The results suggest such reintroductions can be helpful in recovering endangered populations, especially when natural range expansion isn’t a possibility, says Doug Armstrong, a conservation biologist at Massey University in Palmerston North, New Zealand. But Armstrong, who was instrumental in rehabilitation efforts in New Zealand of a honeyeater-like bird called the hihi, also warns that this method won’t work for every threatened species. Lots of factors can lead to failure: selecting an inappropriate site, unpredictable environmental factors, and stress after reintroduction.
Cornell University ecologist Amanda Rodewald says that—even with its upsides—the approach should be seen as a last resort. “With ongoing climate change and habitat destruction, we are likely to be turning to [reintroduction] methods more and more,” she says. “However, taking proactive conservation steps such as habitat protection before a species becomes critically endangered is always going to be the most cost-effective and successful approach.”
(First published by Science magazine on May 5 2017. Available online at: http://www.sciencemag.org/news/2017/05/parachuting-birds-long-lost-territory-may-save-them-extinction)
Electronic tracking or telemetry is a tool used to gain insight into species behaviour. Data gathered through this method helps to expand our knowledge on certain creatures and serves as a stepping stone to developing conservation strategies and informing policy. However, recent research indicates that it may be a double-edged sword.
A paper on research led by Prof Steven Cooke in Conservation Biology illustrates how poachers are using tracking technology to locate and kill the very species it was intended to protect. One method discussed is“cyber poaching”: the act of hacking into GPS collars to track down animals. The paper points to one notable – yet thankfully thwarted – attempt in India involving a Bengal tiger.
Hacking GPS systems takes “serious computing abilities”, but Cooke said it is relatively easy to tamper with basic devices.
“With a simple radio tag, you can buy a receiver for $300 (€280) online, turn the dial until you hear the animal, and go and find it,” the biology professor at Ottawa’s Carleton University told The Irish Times.
Cooke and fellow researchers also looked at how other groups can abuse tracking devices. An example occurred in Banff National Park, where photographers used personal telemetry equipment to locate wildlife in their quest for a perfect snapshot. As a result, Parks Canada implemented a public ban on VHF radio receivers.
Data gathered through telemetry is often made publicly available by researchers, particularly online. The paper describes how open-access data can prove problematic, with the researchers stressing the need to “share data in forms that do not facilitate abuse”.
“Telemetry provides data that people find interesting and easy to understand but there are ways to tell a story without telling exact animal positions,” said Cooke.
Since the paper was released, many people have come forward with examples of tracking and data misuse. A conference on the issue will be held in Australia in June. “We wanted to get the community talking like this so we can act before it is too late,” said Cooke.
Chairman of the Golden Eagle Trust Ronan Hannigan said tracking is an extremely useful tool, especially for monitoring re-released birds. Though he does not view hacking as a threat here, the trust guards sensitive data, particularly with highly-persecuted animals such as peregrines.
To avoid interference, the Golden Eagle Trust strives to keep nest locations private. If information is leaked, however, they find it safer to make it completely public. “Most people become natural custodians for animals if they know they are there and so it becomes too risky for poachers to target them,” said Hannigan.
When deciding to reveal an animal’s location, Dr Colin Lawton from the NUIG zoology department, says he believes it should be treated on a case-by-case basis.
“It depends whether an animal is particularly sensitive to interference,” says Dr Lawton, who has used radio tracking to monitor squirrels without major issue. “We want to be open without causing a problem to the species. Overall though, I’ve a lot of faith in the public.”
While acknowledging that sharing animal locations on social media can prove problematic – an issue touched upon in Cooke’s paper – Lawton finds the tool beneficial for disseminating and collecting information.
Lecturer in wildlife conservation and zoonotic epidemiology in University College Dublin Dr Barry McMahon says that preventing the abuse of telemetry and data requires the management of people.
“It’s not about the management of data but the management of how humans respond to having specific information,” he said.“Before researching a species, you must carry out studies to see where stakeholders are, how they feel about the creature and how they are being treated.”
Whether studying Irish wildlife or a threatened species abroad, he feels this strategy is effective. “If a species is being poached, you must ask, Why are people poaching? They are probably in a terrible situation,” he said.“You would hope that, through working with these groups, they might find an alternative, more sustainable option.”
McMahon is a firm believer in open-access data. Though recognising its drawbacks, he feels legislation will eventually adapt to prevent abuses of this model.
Director of the National Biodiversity Data Centre Dr Liam Lysaght is “not aware” of examples of the abuse of telemetry in Ireland but he too stresses the need for risk assessment studies prior to research or disseminating information. While there is a “small suite of species” for which he feels the need to “blur data”, overall, he says that withholding data does more harm than good.
“Over the last 30 years, nature conservation has suffered tremendously in Ireland,” he said.“Data on rarer species has been restricted as people feel making it available might threaten them. This policy hasn’t helped conservation.”
In recent years, he has witnessed researchers becoming more open. This has raised the profile of certain species and is also key in issues such as informing planning decisions.
“Open access is the only way forward,” he said.“The transition from a protective attitude to an open one has been fundamental to what we do.”
Irish researchers may not view poaching as a concern for most native species, but it is a threat to others worldwide, particularly those perceived as valuable such as rhinoceros and elephant. In an effort to conquer poaching in South Africa’s national parks, global defence and aerospace company Paramount Group decided to aim high – literally.
The Johannesburg-based group recently began training dogs in their Anti-Poaching and Canine Training Academy to parachute from planes and helicopters in tandem with a handler. So far, one dog has been trained, with many more set to follow.
“With the African bush being such a vast wilderness and sometimes inaccessible via vehicle, it became clear that alternative methods of insertion must be considered,” said a spokesperson.“Parachuting enables getting the dogs on the ground as fast as possible.”
Though the parachute initiative is in its infancy, the canine anti-poaching unit has already seen success. One dog, Killer, and his handler have been responsible for the arrest of 115 groups of poachers in Kruger.
“These dogs have proven to be the most effective tool . . . [for] stopping or finding poachers,” said the spokesperson.“Before the use of dogs in anti-poaching operations, the success rate was extremely low due to the vast and dense bush. Today, almost every anti-poaching unit has dogs assisting them.”
(First published in the Irish Times print edition on April 13, 2017. Also available online at: http://www.irishtimes.com/news/science/is-tracking-technology-putting-creatures-in-danger-1.3035028)
My final year dissertation focused on science communication in the Irish print media. At the time of my study in 2014, only one of Ireland’s daily newspapers employed a dedicated science correspondent and had regular science coverage . The aim of my research was to determine whether the existence of a science correspondent within a news organisation affects the quality and quantity of the science coverage. I received a first class honours for my dissertation which can be read here: amy-lewis-dissertation-final-pdf-2014-copy