Wednesday, August 17, 2022

Nurtured by nature Psychological research is advancing our understanding of how time in nature can improve our mental health and sharpen our cognition

reposted from FEATURE Nurtured by nature Psychological research is advancing our understanding of how time in nature can improve our mental health and sharpen our cognition By Kirsten Weir Date created: April 1, 2020 12 min read Vol. 51, No. 3 Print version: page 50 Cognition and the Brain Environment and Population 91 Girl and mother walking through a park Be honest: How much time do you spend staring at a screen each day? For most Americans, that number clocks in at more than 10 hours, according to a 2016 Nielsen Total Audience Report. Our increasing reliance on technology, combined with a global trend toward urban living, means many of us are spending ever less time outdoors—even as scientists compile evidence of the value of getting out into the natural world. From a stroll through a city park to a day spent hiking in the wilderness, exposure to nature has been linked to a host of benefits, including improved attention, lower stress, better mood, reduced risk of psychiatric disorders and even upticks in empathy and cooperation. Most research so far has focused on green spaces such as parks and forests, and researchers are now also beginning to study the benefits of blue spaces, places with river and ocean views. But nature comes in all shapes and sizes, and psychological research is still fine-tuning our understanding of its potential benefits. In the process, scientists are charting a course for policymakers and the public to better tap into the healing powers of Mother Nature. “There is mounting evidence, from dozens and dozens of researchers, that nature has benefits for both physical and psychological human well­being,” says Lisa Nisbet, PhD, a psychologist at Trent University in Ontario, Canada, who studies connectedness to nature. “You can boost your mood just by walking in nature, even in urban nature. And the sense of connection you have with the natural world seems to contribute to happiness even when you’re not physically immersed in nature.” Cognitive benefits Spending time in nature can act as a balm for our busy brains. Both correlational and experimental research have shown that interacting with nature has cognitive benefits—a topic University of Chicago psychologist Marc Berman, PhD, and his student Kathryn Schertz explored in a 2019 review. They reported, for instance, that green spaces near schools promote cognitive development in children and green views near children’s homes promote self-control behaviors. Adults assigned to public housing units in neighborhoods with more green space showed better attentional functioning than those assigned to units with less access to natural environments. And experiments have found that being exposed to natural environments improves working memory, cognitive flexibility and attentional control, while exposure to urban environments is linked to attention deficits (Current Directions in Psychological Science, Vol. 28, No. 5, 2019). Researchers have proposed a number of ideas to explain such findings, as Nisbet and colleagues described in a review of the benefits of connection with nature (Capaldi, C.A., et al., International Journal of Wellbeing, Vol. 5, No. 4, 2015). The biophilia hypothesis argues that since our ancestors evolved in wild settings and relied on the environment for survival, we have an innate drive to connect with nature. The stress reduction hypothesis posits that spending time in nature triggers a physiological response that lowers stress levels. A third idea, attention restoration theory, holds that nature replenishes one’s cognitive resources, restoring the ability to concentrate and pay attention. The truth may be a combination of factors. “Stress reduction and attention restoration are related,” Nisbet points out. “And because of the societal problems we’re dealing with in terms of stress, both of these theories have gotten a lot of attention from researchers.” Experimental findings show how impressive nature’s healing powers can be—just a few moments of green can perk up a tired brain. In one example, Australian researchers asked students to engage in a dull, attention-draining task in which they pressed a computer key when certain numbers flashed on a screen. Students who looked out at a flowering green roof for 40 seconds midway through the task made significantly fewer mistakes than students who paused for 40 seconds to gaze at a concrete rooftop (Lee, K.E., et al., Journal of Environmental Psychology, Vol. 42, No. 1, 2015). Even the sounds of nature may be recuperative. Berman and colleagues found that study participants who listened to nature sounds like crickets chirping and waves crashing performed better on demanding cognitive tests than those who listened to urban sounds like traffic and the clatter of a busy café (Van Hedger, S.C., et. al., Psychonomic Bulletin & Review, Vol. 26, No. 2, 2019). grinning boy standing on his head Nature and happiness While such laboratory experiments are intriguing, they don’t fully capture the diverse benefits that go hand in hand with time spent in the outdoor world, says Cynthia Frantz, PhD, a professor of psychology and environmental studies at Oberlin College in Ohio. “Spending time in nature has cognitive benefits, but it also has emotional and existential benefits that go beyond just being able to solve arithmetic problems more quickly,” she notes. In a review of the research, Gregory Bratman, PhD, an assistant professor at the University of Washington, and colleagues shared evidence that contact with nature is associated with increases in happiness, subjective well-being, positive affect, positive social interactions and a sense of meaning and purpose in life, as well as decreases in mental distress (Science Advances, Vol. 5, No. 7, 2019). Other work suggests that when children get outside, it leaves a lasting impression. In a study of residents of Denmark, researchers used satellite data to assess people’s exposure to green space from birth to age 10, which they compared with longitudinal data on individual mental health outcomes. The researchers examined data from more than 900,000 residents born between 1985 and 2003. They found that children who lived in neighborhoods with more green space had a reduced risk of many psychiatric disorders later in life, including depression, mood disorders, schizophrenia, eating disorders and substance use disorder. For those with the lowest levels of green space exposure during childhood, the risk of developing mental illness was 55% higher than for those who grew up with abundant green space (Engemann, K., et al., PNAS, Vol. 116, No. 11, 2019). There is even evidence that images of nature can be beneficial. Frantz and colleagues compared outcomes of people who walked outside in either natural or urban settings with those of people who watched videos of those settings. They found that any exposure to nature—in person or via video—led to improvements in attention, positive emotions and the ability to reflect on a life problem. But the effects were stronger among those who actually spent time outside (Mayer, F.S., et al., Environment and Behavior, Vol. 41, No. 5, 2009). More recently, scientists have begun exploring whether virtual reality nature experiences are beneficial. In a review of this work, Mathew White, PhD, an environmental psychologist at the University of Exeter in England, and colleagues concluded that while the real deal is best, virtual reality can be a worthwhile substitute for people who are unable to get outdoors, such as those with mobility problems or illness (Neuro­psychiatric Disease and Treatment, Vol. 14, 2018). Nature might also make us nicer—to other people as well as to the planet. John Zelenski, PhD, a professor of psychology at Carleton University in Ontario, Canada, and colleagues showed undergraduates either nature documentaries or videos about architectural landmarks. Then the participants played a fishing game in which they made decisions about how many fish to harvest across multiple seasons. Those who had watched the nature video were more likely to cooperate with other players, and also more likely to make choices that would sustain the fish population (Journal of Environmental Psychology, Vol. 42, No. 1, 2015). In another experiment, Zelenski and his colleagues found that elementary school children acted more prosocially to classmates and strangers after a field trip to a nature school than they did after a visit to an aviation museum (Dopko, R.L., et al., Journal of Environmental Psychology, Vol. 63, No. 1, 2019). Those generous behaviors weren’t attributed to students’ moods, Zelenski and his colleagues found, so it wasn’t simply that spending time in nature made them happier and therefore more giving. Another plausible (though unproven) explanation is the emotion of awe. “There are some hints that awe is associated with generosity, and nature can be a way to induce awe,” he says. “One of the things that may come from awe is the feeling that the individual is part of a much bigger whole.” Experience vs. connection With so many benefits linked to nature, people naturally wonder: How much time outside is enough? White and colleagues took a stab at answering that question by studying a representative sample of nearly 20,000 adults across the United Kingdom. They found people who had spent at least two recreational hours in nature during the previous week reported significantly greater health and well-being. That pattern held true across subgroups including older adults and people with chronic health problems, and the effects were the same whether they got their dose of nature in a single 120-minute session or spread out over the course of the week (Scientific Reports, Vol. 9, No. 1, 2019). “We’re not saying we’ve cracked this nut yet, but this is a first step toward making specific recommendations about how much time in nature is enough,” White says. The amount of time one spends in nature isn’t the only element to consider—it’s also beneficial to feel connected to the natural world even when you’re stuck at a desk. Researchers call this feeling by a variety of names, including nature relatedness, connectedness to nature and inclusion of nature in self, and they’ve developed a number of scales to measure the trait. Whatever you call it, connectedness to nature seems to benefit mood and mental health. In a meta-analysis, Alison Pritchard, PhD, ABPP, at the University of Derby in England, and colleagues found that people who feel more connected to nature have greater eudaimonic well-being—a type of contentment that goes beyond just feeling good and includes having meaningful purpose in life (Journal of Happiness Studies, online first publication, 2019). Zelenski and Nisbet studied whether connection itself is the magic ingredient. They assessed the overlap between connectedness with nature and a general sense of connectedness, such as feeling in tune with one’s friends or community. They found that feeling connected to nature was a significant predictor of happiness even after controlling for the effects of general connectedness (Environment and Behavior, Vol. 46, No. 1, 2014). “People who feel that their self-concept is intertwined with nature report being a bit happier,” says Zelenski. “Nature connectedness isn’t the biggest predictor of happiness, but [the association between the two] is quite consistent.” In fact, nature might help to buffer the effects of loneliness or social isolation. White and his colleagues surveyed 359 U.K. residents about their social connectedness and proximity to nature over the previous week. Social isolation is typically associated with worse subjective well-being. But the researchers found that when people with low social connectedness had high levels of nearby nature, they reported high levels of well­being (Cartwright, B.D.S., et al., International Journal of Environmental Research and Public Health, Vol. 15, No. 6, 2018). “There are people who don’t necessarily want to spend their time with others, but they feel connected to the natural environment, and that can enhance their well-being,” White says. Green and blue spaces It’s clear that getting outside is good for us. Now, scientists are working to determine what types of environments are best. Much attention has gone to green spaces, but White has studied a variety of marine and freshwater environments and found these blue spaces are also good for well-being (Gascon, M., et al., International Journal of Hygiene and Environmental Health, Vol. 220, No. 8, 2017.) In fact, he says, they may even be slightly more restorative than green spaces. There may also be value in trekking to remote locations. In a survey of 4,515 U.K. residents, White found that people reported more connection to nature and felt more restored after visiting rural and coastal locations than they did after spending time in urban green spaces. Areas deemed to be “high environmental quality”—such as nature reserves and protected habitats—were also more beneficial than areas with low biodiversity (Wyles, K.J., et al., Environment and Behavior, Vol. 51, No. 2, 2019). In other work, White and his colleagues found that people who watched nature videos with a diverse mix of flora and fauna reported lower anxiety, more vitality and better mood than those who watched videos featuring less biodiverse landscapes (Wolf, L.J., et al., PLOS ONE, Vol. 12, No. 1, 2017). woman admiring body of water and beautiful hills But there’s an important caveat, White adds: “If you have a break from work and you’ve only got half an hour, then a wild remote place is no use to you at all.” Urban parks and trees also produce positive outcomes. Just like a little exercise is better than none, we should take­ advantage of green and blue spaces wherever and whenever we can. That’s easier said than done, though, especially for people at a socioeconomic disadvantage. Poorer neighborhoods, White notes, are seldom the ones with leafy groves and ocean views. Yet policymakers, city planners, environmental organizations and government agencies are coming around to the importance of natural spaces, and psychologists are offering them their expertise, says White, who has presented his research to groups such as the U.K.’s Department for Environment, Food and Rural Affairs. Organizations and cities are expressing interest in this research, Zelenski says, though many policymakers are waiting to see the results of intervention studies before investing in green infrastructure. One of the United Nations’ sustainable development goals includes the target of providing universal access to safe, inclusive and accessible green and public spaces by 2030. There is urgency in fostering these connections, says Nisbet. Because while people benefit from their connection with the natural world, the environment also benefits when people feel connected and committed to caring for the Earth—and between climate change and habitat loss, the planet is in serious need of some care. “When people are disconnected from nature, they aren’t motivated to work on wicked problems like climate change. We’re losing the environments that contribute to our flourishing,” she says. “The key question is, How do we help people feel connected to nature so we’re motivated to protect the places that will help us thrive?” Key points Spending time in nature is linked to both cognitive benefits and improvements in mood, mental health and emotional well-being.Feeling connected to nature can produce similar benefits to well-being, regardless of how much time one spends outdoors.Both green spaces and blue spaces (aquatic environments) produce well-being benefits. More remote and biodiverse spaces may be particularly helpful, though even urban parks and trees can lead to positive outcomes. Related article Bringing nature into treatment Further reading Environmental Neuroscience Berman, M.G., et al., American Psychologist, 2019 Nature and Mental Health: An Ecosystem Service Perspective Bratman, G.N., et al., Science Advances, 2019 Ecotherapy: Theory, Research and Practice Jordan, M., & Hinds, J. (Eds.), Red Globe Press, 2016

Monday, August 15, 2022

I want to be famous on the Twitter': Fredericton dad goes viral after daughter's tweet

reposted from 'I want to be famous on the Twitter': Fredericton dad goes viral after daughter's tweet Alyson Samson Alyson Samson CTV News Atlantic Video Journalist Follow | Contact Updated June 8, 2022 11:27 a.m. EDT Published June 7, 2022 6:10 p.m. EDT Share facebooktwitterreddit More share options A Fredericton father has gone viral overnight, amassing hundreds of thousands of "likes" on Twitter, after his daughter tweeted about a conversation they had. "So we have Sunday dinner almost every week and we were just sitting around the dinner table and talking about social media and the difference between Instagram and Twitter," Elizabeth Kearns said. "And dad thought that Twitter was just words and when I explained no, you can put your picture up, he said, ‘Well I want to be on the Twitter,'" she said. So Kearns tweeted a photo of her father, Mike Ross, and the likes started rolling in. But the newfound fame hasn't convinced Ross to make his own account just yet. "No and I don't intend to," Ross said. "I mean, Elizabeth asked me what would I be happy with, and I said, 'Oh, if five people like me or like the tweet then that's success,'" he said. Now, with about 300,000 likes, and more than 4,000 comments Tuesday afternoon, people all over the world have jumped on board the wholesome post from the dad and daughter duo. "It's like a snowball," Kearns said. "It's absolutely amazing and as I said to Elizabeth, where are these people? Ireland, Germany, Australia, New Zealand, South Africa, the United States -- the reach and the speed of the reach is mind-blowing," Ross chimed in. Watching the numbers grow and comments roll in has become a bonding activity for the pair. With many Twitter users asking to adopt Ross as their dad, it has also prompted Kearns to pause and reflect. "I realize how lucky I am to have my dad in my life and it's just, this is just one of those silly special fun memories that we're going to laugh about for a long time," Kearns said. They’re also hoping to bring some positivity to the internet, which can sometimes have a negative side. And Ross has this to say to all his newfound fans. "Just be kind to one another and do random acts of kindness, be kind in what you say and what you do. Just be kind." RELATED IMAGES Report an error Report an error Editorial standards & policies Editorial standards & policies Why you can trust CTV News Why you can trust CTV News

Thursday, July 28, 2022

Low serotonin might not cause depression, but why do SSRIs still work?

reposted from Low serotonin might not cause depression, but why do SSRIs still work? Written by Jessica Norris on July 26, 2022 — Fact checked by Hannah Flynn Depression and serotonin levels may not be as closely interlinked as we had thought. Image credit: Aurelien Morissard/Xinhua via Getty Images. Depression is a highly prevalent mental illness. Treatment options for depression are individualized and may include the use of medications and therapy. Researchers have theorized that low serotonin levels cause depression. Data from a recent systematic umbrella review found little evidence linking serotonin levels with depression. Clinical depression is one of the most common mental illnesses, impacting millions of people worldwide. While several factors contribute to depression, one common idea is that it is related to chemical imbalances in the brain, particularly low levels of the chemical serotonin. However, there may be less data supporting this theory than researchers had initially thought. A recent systematic umbrella review published in Molecular PsychiatryTrusted Source found that there is little evidence to support the notion that depression is associated with low serotonin levels. SSRIs as treatment for depression Clinical depression is a serious mental illness that impacts quality of life and well-being. The World Health Organization (WHO) notes that about 280 millionTrusted Source people worldwide live with depression. People with depression experience various symptomsTrusted Source that affect their mood, emotions, and ability to go about their daily lives. The treatment for depressionTrusted Source often involves multiple approaches. For example, people with depression might utilize cognitive behavioral therapy (CBT) to help them work through perceptions and thought patterns, or other forms of talking therapy, including counseling and psychotherapy. Other lifestyle changes can also be considered. Treatment may also include using antidepressants such as selective serotonin reuptake inhibitors (SSRIs). SSRIs increase levels of serotonin in the body. Serotonin is a neurotransmitter that may impact people’s moods and behaviors, and SSRIs can be effective in treating symptoms of depression. However, the theory that serotonin levels are inextricably linked to this condition hails back to the 1960s. The review recently published in Molecular Psychiatry now disputes this long-held notion. Depression’s association with low serotonin The review examined data from systematic reviews, meta-analyses, and large database studies. Researchers did not include animal studies or studies that focused on depression sub-types such as postpartum depression or depression in people with specific physical conditions, such as Parkinson’s. Their research included 17 studies in their analysis. In one-meta analysis, there was weak evidence that low levels of tryptophan might affect people with family histories of depression. Tryptophan lowers the amount of serotonin available. However, most of the data suggested that depression is not associated with low serotonin levels or that low serotonin levels cause depression. Researchers also found some evidence supporting the idea that long-term antidepressant use might actually lower serotonin levels in the body. They note that further research is needed to look into the long-term effects of antidepressants on the body. They also note that the quality of the reviews included in their own analysis was variable. Review author Prof. Joanna Moncrieff, from University College London, summarized the results this way: “The main message of the paper is that scientific evidence accumulated over several decades does not support the theory that depression is caused by a deficiency of serotonin. Since serotonin is the main brain chemical thought to be involved in depression and the one that has been most thoroughly researched in modern times, this means the idea that depression is due to a chemical imbalance is not scientifically established.” Limitations and implications The researchers were thorough in their data collection and analysis methods. However, they note that their review still has several limitations. For example, they point out that some of the non-genetic studies included did not take into account the impact of previous antidepressant use and had small sample sizes. Their ability to analyze components like confounding was limited based on what was done in the studies, and some data were older, indicating the need for further research. The data available suggest that low serotonin levels do not cause depression. However, this does not mean that doctors will stop utilizing antidepressants as a treatment option. Instead, it calls for more research about why antidepressants work the way they do. Prof. Andrea Cipriani, professor of psychiatry at the University of Oxford in the United Kingdom, who was not involved in the study, noted the following to MNT: “This study tried to answer the question: ‘Do depressed people have different levels of serotonin?’ And the authors suggest the answer is ‘no.’ However, a completely different question is whether antidepressants work. This question was not addressed in the paper, and the problem — and the real danger — is that this study is actually used to answer that second question… The possible role of serotonin in depression is a separate question from the antidepressant effects of selective serotonin reuptake inhibitors, and no current theory of antidepressant action makes the assertion that antidepressants work only by correction of a prior corresponding chemical imbalance.” Prof. Moncrieff’s view was that: “Antidepressants were initially suggested to work by rectifying the serotonin abnormality that was thought to underpin depression. As our paper shows, there is no evidence of a serotonin abnormality in depression. This means that we do not actually understand what antidepressants are doing. We need to reevaluate the pros and cons of antidepressant treatment in light of this.” Furthermore, the research may impact how people view the use of antidepressants. People may come to view antidepressants more as part of a comprehensive approach to treatment rather than a “fix.” Prof. Moncrieff explained that “[m]any people have been told that their mood problems are due to a chemical imbalance and that they need antidepressants to put them right.” “This,” she suggested, “has probably contributed to the escalating use of antidepressants over the last three decades. People should be informed that this has not been established, so they can make more informed decisions about whether to use antidepressants.”

Tuesday, July 12, 2022


reposted from DREAM-LIKE SCENES FROM INSIDE A SQUASH COURT, UNLIKE ANY YOU’VE EVER SEEN BEFORE Jul 7, 2022 by Alex Baker 2 Comments What immediately springs to mind when you think of racquet sports? The excitement of the match? The incredible athletic skill required? Or perhaps the weird grunting that often seems to accompany it? Well not for Award-winning Australian Photographer, Brad Walls. The New York-based photographer has released a new series titled ‘Vacant’. Like his previous series “Pools from Above“, it draws inspiration from his fascination with surrealism and geometric art. DIYP caught up with Brad to find out more about his new work, what inspires him to create, and what exciting projects he has up his sleeve for the future. ‘Cross Hair’ “I had always wanted to do a retrofuturistic photoshoot,” Brad says. “I am drawn to the tension between the future and the past. For me, the most prolific element of the 80s was the squash court, so I started there.” He knew he could use the lines of the court to his advantage in strategically breaking up the scenes into halves and thirds. This provides a great foundation compositionally, he explains that he also used the carpet to the same effect. The choreography is deliberate and involves all mid-movement poses, which feel quite detached from the scene. “I enjoy that feeling of dissonance in my imagery, it seduces the viewer to wanting more,” says Brad. ‘Death by Perspective’ Every scene and image is meticulously planned and Brad sketches out every scene he wishes to take. He says that he usually walks into the shoot with about 20-30 frames ranging in priority and difficulty. “I leave 10-15% of the shoot to experiment, however, the squash court didn’t provide much experimentation due to how restrained I was with the variables,” says Brad. ‘Future Passé’ As an artist you are trying to push your work to the next level, finding the new scenes, testing the limits. A 20 square metre box using a drone was the next challenge. I was bound to crash. – Brad Walls ‘Mannequin Road’ “The major challenge was space. I was surprised how much height I did have for the shoot but the challenge was my diagonal frames.” 20 square meters is not a lot of space with a 24mm lens. Brad explains that the DJI Mavic 3 drone had prop guards on and was touching the corners of the court to have enough frame. “I even flew outside the court and over the glass entry doors for many of the shots,” Brad says. Lighting also proved to be a slight issue with the immense amount of white in the scene, but nothing apparently that was too difficult to fix in post. The only post processing work involved the usual adjustments in Lightroom and then moving into Photoshop for stitching the images together and compositing work. ‘Poise’ In creating ‘Vacant’, Walls set out to create a pure, clinical, retrofuturistic theme, using white and pops of red as he states “To combat the claustrophobic nature of a squash court, I filled the space with as much white as possible, including the models wardrobe to avoid the scenes becoming too ‘boxed in’. The futuro wardrobe is used to contrast against the 80’s retro nature of the squash court as Walls states “I’ve always enjoyed Retrofuturism, the tension between the future and the past is intriguing. Movies like Gattaca, Blade Runner and Beyond the Black Rainbow have been pivotal in my understanding of the genre”. ‘Red Luxe’ So what can we expect to see from Brad in the near future? “I’m completing a Ballet project featuring the biggest companies in the world: NYCB & English National Ballet so far, which will be very exciting!” says Brad. Indeed, it does all sound pretty fabulous, if his last two projects are anything to go by we can expect to see some more spectacular images in the not too distant future. ‘Unbalanced’ ‘Pools from Above’ will be published in book format from October of this year and available to pre-order now for $35. You can see more of Brad’s work on his website and Instagram.

Friday, June 24, 2022

Study Links Depression with High Levels of an Amino Acid

 reposted from

Study Links Depression with High Levels of an Amino Acid

Experiments in animals and observations in humans suggest that the amount of proline circulating in one’s plasma has a strong association with depression severity.

black and white image of young man in sunglasses with trees in background
Dan Robitzski
Jun 14, 2022


A growing body of literature ties the gut microbiome to symptoms of depression in a seemingly circular relationship where each affects the other. However, many of the studies on this relationship merely link certain bacterial populations or diets to major depressive disorder—leaving open critical questions about the underlying mechanisms of how the gut microbes might influence depression.

Research published last month (May 3) in Cell Metabolism takes an important step toward filling such gaps, demonstrating in multiple animal species that there is likely a causative relationship between depression severity and serum levels of the nonessential amino acid proline, which the study finds depend on both diet and the activity of proline-metabolizing bacteria in the gut.

“To the best of my knowledge, this is the first time that a team actually demonstrates a causal relationship between proline intake and depressive behavior,” King’s College London metabolism researcher Sandrine Claus, who didn’t work on the study and is also chief scientific officer of the microbiome therapeutics company YSOPIA Bioscience, tells The Scientist over email. “I am unaware of a proline-mediated gut-brain axis. This is therefore a completely novel mechanism of action.”

Depression diet: the effects of proline

Previous research had found that proline, among other dietary compounds, seems to play a role in major depressive disorder, but “we found increased levels not only [in] major depression but also in subjects with moderate depression,” study coauthor José Manuel Fernández-Real, a researcher at the Girona Biomedical Research Institute and Dr. Josep Trueta Hospital, both located in Spain, explains. Indeed, the severity of the symptoms correlated with the subjects’ circulating proline.

Fernández-Real and his colleagues uncovered this when they compared people’s responses on an 80-item food intake questionnaire with scores on the Patient Health Questionnaire-9 (PHQ-9), a common clinical survey for diagnosing and measuring the severity of a person’s depression. Out of all the dietary nutrients in the questionnaire, Fernández-Real says, the one “most associated with depressive traits was precisely proline.” Blood tests in the same participants solidified the correlation between proline and depressive traits.

See “Gut Microbes May Play a Role in Mental Health Disorders

However, some discrepancies emerged within the data that demanded a closer look. “Not all subjects with increased proline in the diet had increased proline in the plasma,” hinting that some yet-undiscovered factor was involved, Fernández-Real explains. In search of that explanation, he and the other researchers determined the microbiome compositions of the human participants.

The paper notes that most previous studies attempting to do the same failed to achieve bacterial species-level resolution and have reached inconclusive and conflicting findings. But Fernández-Real and colleagues employed a multi-omics approach that allowed them to link microbial function to the specific biological pathways associated with depression, granting their study a level of resolution that Fernández-Real says was lacking from what he describes as underpowered previous studies.

In the study participants, plasma proline levels were associated with the presence and activity of specific gut bacteria—people with high proline consumption and higher plasma proline levels had different microbiome compositions than those who consumed the same amount of proline but had less circulating in their blood. Furthermore, the team found that the microbial communities of the former were associated with more severe depression.

How the gut microbiome influences depression

To determine whether there’s a direct link between proline and depression, the researchers revisited and modified mouse and Drosophila melanogaster models that they’d previously used to study how the microbiome influenced cognitive abilities.

See “Bacterial Metabolite May Regulate Cognition in Mice

The researchers fed 10 mice a standard diet and another 10 a proline-supplemented diet, then subjected them to stressors typically used to trigger depression-like behaviors. After six weeks, the experimental group had significantly higher proline levels circulating in their plasma and exhibited more signs of depressive behaviors, such as a disinterest in sugar water and decreased mobility during a tail suspension test.

To see how the microbiome factored in, the researchers took fecal samples from 20 human volunteers (nine of whom had high proline levels and all of whom demonstrated a direct correlation between their PHQ-9 score and circulating plasma proline) and put them into antibiotic-treated mice, effectively transferring the human microbiomes into the animals. When the mice were subjected to another test meant to induce depressive behaviors, the researchers found that the mice’s behavior correlated with the PHQ-9 scores—and therefore circulating proline levels—of their donors as well as the mix of microbes now residing in their guts.

The data demonstrated that “a particular microbiota metabolizes proline and is critical to develop more or less depressive symptoms,” says Fernández-Real.

See “Human Gut Microbe Transplant Alters Mouse Behavior

The researchers also conducted RNA sequencing of the animals’ prefrontal cortex, a region of the brain associated with cognition. That revealed that genes related to depressive behaviors had been upregulated following fecal transplantation—and that expression of the proline transporter gene Slc6a20 in the brain correlated with the mice’s behavior and their microbe donors’ PHQ-9 scores.

“The microbiota from subjects with the highest depression scores induced emotional traits in the mice,” says Fernández-Real. “Interestingly, the prefrontal cortex of transplanted mice showed increased expression of genes . . . that we also found in the intestine of subjects with increased proline intake.” 

From there, the researchers moved on to Drosophila experiments, subjecting both wild type control flies and those with downregulated CG43066—the Drosophila version of sl6a20—to stressors to see if the transporters affect whether the animals exhibit depressive behaviors. They then ran the same tests on Drosophila colonized with the bacteria found to increase or decrease proline metabolism in the prior experiments. Downregulating the proline transporter gene or colonizing the Drosophila with specific bacteria, especially certain Lactobacillus species, seemed to protect the flies from depressive behavior, the study found.

Animal depression, human questions

The researchers weren’t able to conduct similar experiments in people, which they concede limits the conclusions that can be drawn from their work. Going forward, Fernández-Real says it will be important to test, for example, “whether diets with different proline contents influence depressive traits and depressive symptomology.”

Chrysi Sergaki, a microbiome researcher at the Medicines & Healthcare products Regulatory Agency in the UK who did not work on the study, tells The Scientist over email that “using these [animal] models is a start. They can help us understand the impact of the microbiome on brain function, but that doesn’t necessarily mean that it will work the same way in humans.” Still, she says that because similar experiments can’t be performed on humans, the animal models used in the new study can grant researchers “a deeper understanding of how the microbiome can influence the functions of the organism they live in,” adding that “that knowledge can be valuable in the way we think about the microbiome when we move to humans.”

See “Distinct Microbiome and Metabolites Linked with Depression

Claus expresses similar sentiments. “Modeling depressive behaviors in animals is . . . very challenging,” she writes. “I actually thought that the drosophila model was interesting despite the fact that we cannot directly translate behavioral observations from drosophila to humans. These are useful to study mechanisms of action though.”

Still, Claus adds that a lack of data on circulating proline levels in the mouse model, combined with repeated reanalysis of the same cohort of people, make it difficult to draw definitive conclusions about the mechanism of microbial proline metabolism and its link to depression.

“The authors keep reanalyzing the same cohort, insisting that they always find a consistent microbial signature with PHQ-9 and proline,” Claus writes. “But this is not surprising since proline is correlated to PHQ-9 score in this cohort, and PHQ-9 score is correlated with a microbial signature.”

Sergaki applauds the study authors for describing the limitations of their work, adding that microbiome studies are notoriously difficult to reproduce and therefore validate. “I think all microbiome scientists look at these studies with a critical eye,” she tells The Scientist. “The authors mention certain limitations of their study which are quite important. The biggest question is always this: correlation or causation? Due to the complexity of the system, this is very difficult to answer.”

Thursday, June 23, 2022

Algorithm could diagnose Alzheimer’s disease from a single brain scan

 reposted from

Algorithm could diagnose Alzheimer’s disease from a single brain scan

Published: 20 June 2022

A single MRI scan of the brain could be enough to diagnose Alzheimer’s disease, according to new research supported by NIHR.

Researchers developed an algorithm to analyse structural features shown on brain MRI scans, including in regions not previously associated with Alzheimer’s. This machine learning technology was able to accurately predict the existence of Alzheimer’s disease and identify the disease at an early stage, when it can be very difficult to diagnose.

Alzheimer’s disease is the most common form of dementia, affecting over half a million people in the UK. Although most people with Alzheimer’s disease develop it after the age of 65, people under this age can develop it too. The most frequent symptoms of dementia are memory loss and difficulties with thinking, problem solving and language.

Currently lots of tests are used to diagnose Alzheimer’s disease, including memory and cognitive tests and brain scans. The scans are used to check for protein deposits in the brain and shrinkage of the hippocampus, the area of the brain linked to memory. All of these tests can take several weeks, both to arrange and to process.

Getting a diagnosis quickly at an early stage helps patients access help and support, get treatment to manage their symptoms, and plan for the future. Being able to accurately identify patients at an early stage of the disease will also help researchers to understand the brain changes that trigger Alzheimer’s disease, and support development and trials of new treatments.

The researchers, supported by Imperial Biomedical Research Centre, studied just one of the tests currently used to diagnose Alzheimer’s disease - an MRI scan. They adapted an algorithm developed for use in classifying cancer tumours and applied it to MRI scans of the brain.

The researchers divided the brain into 115 regions and allocated 660 different features, such as size, shape and texture. They then trained the algorithm to identify where changes to these features could accurately predict the existence of Alzheimer’s disease.

Using data from the Alzheimer’s Disease Neuroimaging Initiative, the team tested their approach on brain scans from over 400 patients with early and later stage Alzheimer’s, healthy controls and patients with other neurological conditions, including frontotemporal dementia and Parkinson’s disease. They also tested it with data from more than 80 patients undergoing diagnostic tests for Alzheimer’s at Imperial College Healthcare NHS Trust.

The research, published in the Nature Portfolio Journal Communications Medicine, found that in 98% of cases, the MRI-based machine learning system alone could accurately predict whether the patient had Alzheimer’s disease or not. It was also able to distinguish between early and late-stage Alzheimer’s with fairly high accuracy, in 79% of patients.

The new system spotted changes in areas of the brain not previously associated with Alzheimer’s disease, including the cerebellum (the part of the brain that coordinates and regulates physical activity) and the ventral diencephalon (linked to the senses, sight and hearing). This opens up potential new avenues for research into these areas and their links to Alzheimer’s disease.

Professor Eric Aboagye, from Imperial’s Department of Surgery and Cancer, who led the research, said: “Currently no other simple and widely available methods can predict Alzheimer’s disease with this level of accuracy, so our research is an important step forward. Many patients who present with Alzheimer’s at memory clinics do also have other neurological conditions, but even within this group our system could pick out those patients who had Alzheimer’s from those who did not.

“Waiting for a diagnosis can be a horrible experience for patients and their families. If we could cut down the amount of time they have to wait, make diagnosis a simpler process, and reduce some of the uncertainty, that would help a great deal. Our new approach could also identify early-stage patients for clinical trials of new drug treatments or lifestyle changes, which is currently very hard to do.”

Dr Paresh Malhotra, who is a consultant neurologist at Imperial College Healthcare NHS Trust and a researcher in Imperial’s Department of Brain Sciences, said: “Although neuroradiologists already interpret MRI scans to help diagnose Alzheimer’s, there are likely to be features of the scans that aren’t visible, even to specialists. Using an algorithm able to select texture and subtle structural features in the brain that are affected by Alzheimer’s could really enhance the information we can gain from standard imaging techniques.”

Read more about this research on the NIHR imperial BRC website

Wednesday, June 15, 2022

Spilling the Tea: Insect DNA Shows Up in World’s Top Beverage

 reposted from

Spilling the Tea: Insect DNA Shows Up in World’s Top Beverage

The Scientist speaks with Trier University’s Henrik Krehenwinkel, whose group recently detected traces of hundreds of arthropod species from a sample of dried plants—in this case, the contents of a tea bag.

Shawna headshot
Shawna Williams
Jun 14, 2022


How do you monitor which species live in an area? In addition to traditional ecological tools such as camera traps, researchers have reported new methods in recent years that allow them to detect minute traces of DNA known as environmental DNA, or eDNA, that animals leave behind in water and even air. In a study published June 15 in Biology Letters, a group reports picking up eDNA from a new source: dried plant material. The team purchased tea from grocery stores, and were able to detect hundreds of species of arthropods in just one bag. 

We asked study coauthor Henrick Krehenwinkel, an ecological geneticist at Trier University in Germany who focuses on the ways in which arthropod communities have changed over time due to human influence, to spill the tea about why his group decided to use eDNA to investigate which critters have been munching on plants. 

TS: Why did you decide in this case to focus on tea? 

Henrik KrehenwinkelWe need [a] time series to understand how insects have changed. When insect decline studies were first published, a lot of people complained [that] there is no real long-term data.  

See “Germany Sees Drastic Decrease in Insects” 

We have a specimen bank here in Trier. They’re collecting leaves from different trees in Germany. They’ve been doing this for 35 years; they go to all kinds of different ecosystems. . . . And what I asked myself is, ‘Couldn’t you also monitor the DNA of the insects which have lived on this leaf?’ . . . We basically did a test experiment where we took these samples, which are frozen in liquid nitrogen, so they’re perfectly stored for DNA preservation . . . and isolated DNA from them, and reconstructed arthropod communities. This is actually another study which is currently in review, where we have basically reconstructed insect community change in German forest ecosystems over the past 35 years.  

So we can extract eDNA from a perfectly frozen leaf. . . . What I asked myself is, “Can you also use other substrates to basically extract the DNA from arthropods?” And is the DNA still stable in other types of substrates? . . . Plant collections in museums, could they actually be useful to understand how insect communities have changed? . . . There are studies saying that . . . if an insect bites into a leaf, it will leave a DNA trace; a little bit of saliva is enough. It’s basically like [how] the criminal breaking into your house, touching your window, will leave their DNA; the insect will leave its DNA when it bites into the leaf. And there are studies saying that this DNA is not very stable, it will be quickly degraded by UV light or washed away by rain. But I was thinking in an herbarium record, the DNA is stored dry and dark, which [are] actually ideal conditions to maintain it.  

Before we started working on herbaria records, we thought we should try something which is kind of comparable to herbarium records. . . . Structure-wise, [tea is] very similar to herbarium record. It’s basically a dried plant which is stored dark and dry. . . . And the DNA should be very stable.  

It’s all driven by our hope to understand insect community change and being able to find new substrates which allow us to travel back in time. . . . You can collect a plant in the field, basically a flower. And you can dry this flower just using silica gel. . . . It’s a substance which is completely harmless, but it’s extremely hydrophilic. . . . If you, for example, put a flower into a little envelope, and then you put it in a Ziploc freezer bag together with a little bit of silica gel, within one day approximately, the flower will be completely dry. . . . And we could in theory even store them at room temperature, we wouldn’t have to worry to put it all in liquid nitrogen or to wash the plant right away . . . you don’t have to carry water in the field, all you need is a little bit of silica gel, an envelope, and a Ziploc bag.  

Another attractive side effect is that what’s very interesting for us ecologists is not only who is at a site, so how many insect species are at a site, . . . but we also want to know how do these insects interact and what do they eat. For example, we know that many insect species are very specific, only living on a certain plant, and when this plant disappears, the insect disappears. . . . Surprisingly, we know very little about these interactions, we know very little about what insect is limited to a certain plant species. We know this pretty well for pest species, but we do not know this pretty well for many other species of insects. . . . And this is a way of very quickly finding this out by basically sampling plant material and being able to associate the insects living on the plant.  

TS: Was there anything about the results of this study that surprised you? 

HK: What really surprised me was the high diversity we detected. . . . We took one tea bag, and . . . I think it was from 100 [or] 150 milligrams of dried plant material, we extracted DNA. And we found in green tea up to 400 species of insects in a single tea bag. . . . That really surprised me. And the reason probably is that this tea, it’s ground to a relatively fine powder. So the eDNA [from all parts of the tea field] gets distributed.  

TS: As far as applying this to herbaria samples, would you need just a relatively small piece of that sample, or could it be an issue that these are rare and very old samples, and you don't want to be grinding up a big chunk of them. 

HK: We’ve been thinking about this, and there’s two options. One is to just very carefully treat the herbarium sample. We’re now testing if you can also just carefully wash the sample, for example, and kind of wash off the traces which are stuck to the sample.  

Then of course, there’s herbaria where they’re actually happy if you do something with them. [H]ere at this university, we have a retired botany professor, and she has very large herbaria she has collected during her tenure. . . . They don’t have a huge scientific value for her, and she would be fine if I grind them up. . . . We’re just testing this, so I cannot give you any results on this yet, but it looks like we are actually able to extract insect DNA out of this as well. . . . And then move back to that same place—she has exact collection sites—I just drive back there, collect the same plant again, and then I can compare how was the insect community 50 years ago when she collected it or 30 years ago when she collected again, and then compare it to how is the insect community on that plant today.  

But of course, generally these collections are very precious and we are developing methods to carefully extract DNA from this without damaging the specimen. This is something we’re just starting now. Seeing how well it worked with tea, I’m now confident that we could also move into other samples like these herbaria. 

TS: Are you a tea drinker yourself? 

HK: I drink coffee actually. . . . And I fear coffee probably is not well suited for it because coffee is roasted. And what DNA really doesn’t like is being heated up to a very high temperature for a long time . . . . We have not tried it yet, but I fear coffee is probably not the best choice for this kind of experiment. 

Editor’s note: This interview has been edited for brevity.