Exercise can provide relief for dry, itchy eyes
Making time for regular exercise can make your eyes feel better
February 3, 2022
Science Daily/University of Waterloo
A team led by researchers from the University of Waterloo discovered that a significant increase in tear secretion and tear film stability after participating in aerobic exercise can be another remedy for relieving dry, itchy eyes.
Every time we blink, our eyes are covered in tear film -- an essential protective coating necessary for maintaining healthy ocular function. Healthy tear film comprises three layers-oil, water, and mucin-that work together to hydrate the ocular surface and protect against infection-causing irritants like dust or dirt.
When any part of the tear film becomes unstable, the ocular surface can develop dry spots, causing eye symptoms like itchiness or stinging and burning sensations.
"With so much of our activity tied to screen usage, dry eye symptoms are becoming increasingly common," said Heinz Otchere, a PhD candidate in vision science at Waterloo. "Instead of having to use eye drops or other alternative treatments, our study aimed to determine if remaining physically active can be an effective preventative measure against dryness."
Fifty-two participants were divided into two groups -- athlete and non-athlete -- to participate in an exercise session. Participants in the athlete group exercised at least five times per week, while non-athlete participants exercised no more than once per week. Researchers, which included experts from the University of Cape Coast in Ghana, performed visual examinations before and five minutes after each exercise session, where tear secretion and tear break-up time were assessed.
While participants in the athlete group showed the largest increase, Otchere says all participants experienced a meaningful boost in tear quantity and tear film stability after the exercise session.
"It can be challenging for people to regularly exercise when the demand is there to work increasingly longer hours in front of screens," Otchere said. "However, our findings show physical activity can be really important for not just our overall well-being, but for our ocular health too."
https://www.sciencedaily.com/releases/2022/02/220203083607.htm
Afternoon napping linked to better mental agility
Associated with better locational awareness, verbal fluency, and working memory
January 25, 2021
Science Daily/BMJ
Taking a regular afternoon nap may be linked to better mental agility, suggests research published in the online journal General Psychiatry.
It seems to be associated with better locational awareness, verbal fluency, and working memory, the findings indicate.
Longer life expectancy and the associated neurodegenerative changes that accompany it, raise the prospect of dementia, with around 1 in 10 people over the age of 65 affected in the developed world.
As people age, their sleep patterns change, with afternoon naps becoming more frequent. But research published to date hasn't reached any consensus on whether afternoon naps might help to stave off cognitive decline and dementia in older people or whether they might be a symptom of dementia.
The researchers explored this further in 2214 ostensibly healthy people aged at least 60 and resident in several large cities around China, including Beijing, Shanghai, and Xian.
In all, 1534 took a regular afternoon nap, while 680 didn't. All participants underwent a series of health checks and cognitive assessments, including the Mini Mental State Exam (MMSE) to check for dementia.
The average length of night time sleep was around 6.5 hours in both groups.
Afternoon naps were defined as periods of at least five consecutive minutes of sleep, but no more than 2 hours, and taken after lunch. Participants were asked how often they napped during the week; this ranged from once a week to every day.
The dementia screening tests included 30 items that measured several aspects of cognitive ability, and higher function, including visuo-spatial skills, working memory, attention span, problem solving, locational awareness and verbal fluency.
The MMSE cognitive performance scores were significantly higher among the nappers than they were among those who didn't nap. And there were significant differences in locational awareness, verbal fluency, and memory.
This is an observational study, and so can't establish cause. And there was no information on the duration or timing of the naps taken, which may be important.
But there are some possible explanations for the observations found, say the researchers.
One theory is that inflammation is a mediator between mid-day naps and poor health outcomes; inflammatory chemicals have an important role in sleep disorders, note the researchers.
Sleep regulates the body's immune response and napping is thought to be an evolved response to inflammation; people with higher levels of inflammation also nap more often, explain the researchers.
https://www.sciencedaily.com/releases/2021/01/210125191846.htm
Newly discovered subset of brain cells fight inflammation with instructions from the gut
January 25, 2021
Science Daily/Brigham and Women's Hospital
Astrocytes are the most abundant type of cells within the central nervous system (CNS), but they remain poorly characterized. Researchers have long assumed that astrocytes' primary function is to provide nutrients and support for the brain's more closely scrutinized nerve cells; over the years, however, increasing evidence has shown that astrocytes can also actively promote neurodegeneration, inflammation, and neurological diseases. Now, a team led by researchers from Brigham and Women's Hospital, has shown that a specific astrocyte sub-population can do the opposite, instead serving a protective, anti-inflammatory function within the brain based on signals regulated by the bacteria that reside in the gut. Findings on the new anti-inflammation pathway are published in Nature.
"Over the years, many labs, including mine, have identified important roles for astrocytes in promoting neurological diseases," said corresponding author Francisco Quintana, PhD, of the Ann Romney Center for Neurologic Diseases at the Brigham. "This is the first case in which we're showing that at least a subset of these cells (astrocytes) can prevent inflammation. The reason we haven't seen this before was because we were studying these cells as if they were uniform, or one single cell type. But now we have the resolution to see the differences between these cells."
The researchers used refined gene- and protein-analysis tools to identify the novel astrocyte subset. The astrocyte population resides close to the meninges (the membrane enclosing the brain) and expresses a protein called LAMP1, along with a protein called TRAIL, which can induce the death of other cells. These features help the LAMP1+TRAIL+ astrocytes limit CNS inflammation by inducing cell death in T-cells that promote inflammation.
To determine what mechanism controls LAMP1+TRAIL+ astrocytes in the brain, the researchers performed a series of tests using the gene-editing tool CRISPR-Cas9. They found that a particular signaling molecule, called interferon-gamma, regulates TRAIL expression. Moreover, they found that the gut microbiome induces the expression of interferon-gamma in cells that circulate through the body and ultimately reach the meninges, where they can promote astrocyte anti-inflammatory activities.
Understanding the mechanisms driving the anti-inflammatory functions of LAMP1+TRAIL+ astrocytes could enable researchers to develop therapeutic approaches to combat neurological diseases, like multiple sclerosis. For example, they are exploring probiotic candidates that can be used to regulate the astrocytes' anti-inflammatory activity. Additionally, the research team's more recent data indicates that certain brain tumors exploit this pathway to evade the body's immune response. The investigators are therefore developing cancer immunotherapies to retaliate against the tumors' attacks.
"Finding microbiome-controlled anti-inflammatory subsets of astrocytes is an important advance in our understanding of CNS inflammation and its regulation," Quintana said. "This is a very novel mechanism by which the gut controls inflammation in the brain. It guides new therapies for neurological diseases, and we believe that this mechanism could contribute to the pathogenesis of brain tumors."
Quintana's lab identified the only other subset of astrocyte known to be regulated by the gut microbiome in 2016, but the investigators believe that there are likely others. "It's becoming clear that the gut flora are important in many diseases," he said. "We're lucky that we've been leading the charge to identify different subsets of astrocytes and the mechanisms that control them. We have a list of other populations of astrocytes, and we're working to see how the gut flora may control them."
https://www.sciencedaily.com/releases/2021/01/210125191812.htm
Newly discovered subset of brain cells fight inflammation with instructions from the gut
January 25, 2021
Science Daily/Brigham and Women's Hospital
Astrocytes are the most abundant type of cells within the central nervous system (CNS), but they remain poorly characterized. Researchers have long assumed that astrocytes' primary function is to provide nutrients and support for the brain's more closely scrutinized nerve cells; over the years, however, increasing evidence has shown that astrocytes can also actively promote neurodegeneration, inflammation, and neurological diseases. Now, a team led by researchers from Brigham and Women's Hospital, has shown that a specific astrocyte sub-population can do the opposite, instead serving a protective, anti-inflammatory function within the brain based on signals regulated by the bacteria that reside in the gut. Findings on the new anti-inflammation pathway are published in Nature.
"Over the years, many labs, including mine, have identified important roles for astrocytes in promoting neurological diseases," said corresponding author Francisco Quintana, PhD, of the Ann Romney Center for Neurologic Diseases at the Brigham. "This is the first case in which we're showing that at least a subset of these cells (astrocytes) can prevent inflammation. The reason we haven't seen this before was because we were studying these cells as if they were uniform, or one single cell type. But now we have the resolution to see the differences between these cells."
The researchers used refined gene- and protein-analysis tools to identify the novel astrocyte subset. The astrocyte population resides close to the meninges (the membrane enclosing the brain) and expresses a protein called LAMP1, along with a protein called TRAIL, which can induce the death of other cells. These features help the LAMP1+TRAIL+ astrocytes limit CNS inflammation by inducing cell death in T-cells that promote inflammation.
To determine what mechanism controls LAMP1+TRAIL+ astrocytes in the brain, the researchers performed a series of tests using the gene-editing tool CRISPR-Cas9. They found that a particular signaling molecule, called interferon-gamma, regulates TRAIL expression. Moreover, they found that the gut microbiome induces the expression of interferon-gamma in cells that circulate through the body and ultimately reach the meninges, where they can promote astrocyte anti-inflammatory activities.
Understanding the mechanisms driving the anti-inflammatory functions of LAMP1+TRAIL+ astrocytes could enable researchers to develop therapeutic approaches to combat neurological diseases, like multiple sclerosis. For example, they are exploring probiotic candidates that can be used to regulate the astrocytes' anti-inflammatory activity. Additionally, the research team's more recent data indicates that certain brain tumors exploit this pathway to evade the body's immune response. The investigators are therefore developing cancer immunotherapies to retaliate against the tumors' attacks.
"Finding microbiome-controlled anti-inflammatory subsets of astrocytes is an important advance in our understanding of CNS inflammation and its regulation," Quintana said. "This is a very novel mechanism by which the gut controls inflammation in the brain. It guides new therapies for neurological diseases, and we believe that this mechanism could contribute to the pathogenesis of brain tumors."
Quintana's lab identified the only other subset of astrocyte known to be regulated by the gut microbiome in 2016, but the investigators believe that there are likely others. "It's becoming clear that the gut flora are important in many diseases," he said. "We're lucky that we've been leading the charge to identify different subsets of astrocytes and the mechanisms that control them. We have a list of other populations of astrocytes, and we're working to see how the gut flora may control them."
https://www.sciencedaily.com/releases/2021/01/210125191812.htm
Street trees close to the home may reduce the risk of depression
Researchers show positive effect of urban nature on mental health
January 25, 2021
Science Daily/German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
Daily contact with trees in the street may reduce the need for antidepressants. Street tree planting in cities may be a nature-based solution in urban planning to reduce the risk of depression, also addressing climate change and biodiversity loss.
Depression, especially in urban areas, is on the rise, now more than ever. Mental health outcomes are influenced by, among other things, the type of environment where one lives. Former studies show that urban greenspace has a positive benefit on people experiencing mental ill health, but most of these studies used self-reported measures, which makes it difficult to compare the results and generalise conclusions on the effects of urban greenspace on mental health.
An interdisciplinary research team of UFZ, iDiv and Leipzig University tried to improve this issue by involving an objective indicator: prescriptions of antidepressants. To find out whether a specific type of 'everyday' green space -- street trees dotting the neighbourhood sidewalks -- could positively influence mental health, they focused on the questions, how the number and type of street trees and their proximity close to home correlated to the number of antidepressants prescribed.
The researchers analysed data from almost 10,000 Leipzig inhabitants, a mid-size city in Germany, who took part in the LIFE-Adult health study running at the University of Leipzig Medical Faculty. Combining that with data on the number and species type of street trees throughout the city of Leipzig, the researchers were able to identify the association between antidepressants prescriptions and the number of street trees at different distances from people's homes. Results were controlled for other factors known to be associated with depression, such as employment, gender, age, and body weight.
More trees immediately around the home (less than 100 meters) was associated with a reduced risk of being prescribed antidepressant medication. This association was especially strong for deprived groups. As these social groups are at the greatest risk for being prescribed antidepressants in Germany, street trees in cities can thereby serve as a nature-based solution for good mental health, the researchers write. At the same time, street trees may also help reduce the 'gap' in health inequality between economically different social groups. No association of tree types, however, and depression could be shown in this study.
"Our finding suggests that street trees -- a small scale, publicly accessible form of urban greenspace -- can help close the gap in health inequalities between economically different social groups," says lead author of the study Dr Melissa Marselle. "This is good news because street trees are relatively easy to achieve and their number can be increased without much planning effort." As an environmental psychologist, she conducted the research at UFZ and iDiv and is now based at the De Montford University of Leicester, UK. Marselle hopes that the research "should prompt local councils to plant street trees to urban areas as a way to improve mental health and reduce social inequalities. Street trees should be planted equally in residential areas to ensure those who are socially disadvantaged have equal access to receive its health benefits."
"Importantly, most planning guidance for urban greenspace is often based on purposeful visits for recreation," adds Dr Diana Bowler (iDiv, FSU, UFZ), data analyst in the team. "Our study shows that everyday nature close to home -- the biodiversity you see out of the window or when walking or driving to work, school or shopping -- is important for mental health." This finding is especially now in times of the COVID-19 lock-downs, Bowler adds.
And it's not only human health which could benefit. "We propose that adding street trees in residential urban areas is a nature-based solution that may not only promote mental health, but can also contribute to climate change mitigation and biodiversity conservation," says senior author Prof Aletta Bonn, who leads the department of ecosystem services at UFZ, iDiv and Friedrich-Schiller-University Jena. "To create these synergy effects, you don't even need large-scale expensive parks: more trees along the streets will do the trick. And that's a relatively inexpensive measure."
"This scientific contribution can be a foundation for city planners to save and, possibly, improve the life quality for inhabitants, in particular, in densely populated areas and in central city areas," adds Prof Toralf Kirsten from Leipzig University. "Therefore, this aspect should be taken into account when city areas are recreated and planned, despite high and increasing land cover costs. A healthy life of all living being is unaffordable."
https://www.sciencedaily.com/releases/2021/01/210125113124.htm
Lack of sleep, stress can lead to symptoms resembling concussion
Study suggests baseline symptoms may help interpret recovery scores
January 22, 2021
Science Daily/Ohio State University
A new study suggests that a lot of people might be going through life with symptoms that resemble concussion -- a finding supporting researchers' argument that athletes recovering from a brain injury should be assessed and treated on a highly individualized basis.
In the national study, between 11% and 27% of healthy college athletes with no history of a recent concussion reported combinations of symptoms that met criteria for post-concussion syndrome (PCS) as defined by an international classification system. Among the nearly 31,000 student-athletes surveyed, three factors stood out as the most likely to predict PCS-like symptoms: lack of sleep, pre-existing mental health problems and stress.
The participants were cadets from four U.S. military service academies -- who undergo rigorous training and are required to participate in athletics -- and students who competed in NCAA sports at 26 U.S. higher education institutions.
Beyond the substantial numbers of students who reported clusters of PCS-like symptoms, between one-half and three-quarters of all of the athletes surveyed reported one or more symptoms commonly experienced by people who've had a concussion, the most common being fatigue or low energy and drowsiness.
"The numbers were high, and were consistent with previous research in this area, but it is quite shocking," said study lead author Jaclyn Caccese, assistant professor in The Ohio State University School of Health and Rehabilitation Sciences. "These are elite athletes who are physically fit, and they are experiencing that many symptoms commonly reported following concussion. So looking across the general population, they'd probably have even more."
It's important to understand that there are multiple sources of these symptoms, researchers say, so that student-athletes' post-concussion care zeroes in on symptoms caused by the injury. In addition, knowing athletes' medical history and baseline symptom status may help clinicians predict which pre-existing factors could contribute to a slower recovery from a concussion.
"When a patient comes into a clinic and they are a month or more out from their most recent concussion, we need to know what symptoms they were experiencing before their concussion to know if their symptoms are attributable to their concussion or something else. Then we can start treating the concussion-related symptoms to hopefully help people recover more quickly," Caccese said.
This study, published last week in the journal Sports Medicine, was conducted by the Concussion Assessment, Research and Education (CARE) Consortium established by the NCAA and U.S. Department of Defense. Caccese completed the research while she was a PhD student and postdoctoral researcher at the University of Delaware, a consortium member institution.
The initiative is designed to fill gaps in knowledge about concussion effects and recovery among student-athletes at colleges, universities and military service academies by collecting and analyzing data on men and women who compete in a range of sports and undergo military training.
Participants in this study included 12,039 military service academy cadets and 18,548 NCAA student-athletes who completed the Sport Concussion Assessment Tool symptom evaluation as part of the consortium's baseline testing. The consortium also collected demographic data and personal and family medical histories from participants.
Statistical analyses showed which factors in athletes' medical histories were most closely associated with reports of symptoms that aligned with PCS criteria. Among cadets, 17.8% of men and 27.6% of women reported a cluster of symptoms that met PCS criteria. Among NCAA athletes, 11.4% of men and 20% of women reported combined symptoms that mimicked the PCS criteria. (Caccese said the varied timing of data collection at military service academies compared to NCAA preseason testing likely contributed to the symptoms reported by a higher percentage of cadets.)
For both groups, sleep problems -- and particularly insufficient sleep the night before the test -- and pre-existing psychiatric disorders were the most predictive conditions, and a history of migraines also contributed to symptoms that met PCS criteria. In cadets, academic problems and being a first-year student increased odds of having symptoms that met PCS criteria, and in NCAA athletes, a history of ADHD or depression contributed to meeting PCS criteria.
The International Classification of Diseases, Tenth Revision uses the term post-concussion syndrome for persistent symptoms following concussion, although the cause or causes of these symptoms can be difficult to determine. Symptoms range from persistent headaches, dizziness and fatigue to anxiety, insomnia and loss of concentration and memory.
A complicating factor with high symptom reporting is that recognizing concussion and determining return to play is based on reported symptoms. And while some symptoms may be more closely connected to concussion than others -- such as dizziness, pressure in the head, or sensitivity to light or noise -- others, like fatigue, drowsiness and even headaches, can be linked to a variety of causes.
"Perhaps we can create a battery of symptoms more specific to concussion," Caccese said. "That is another project in this series -- trying to see if there are groups of symptoms or specific symptoms that may be more able to identify individuals with concussion."
The CARE Consortium also aims to identify factors that will help predict outcomes in student-athletes and cadets who suffer concussions.
"This hopefully not only shows clinicians that we need to consider how people would have presented before injury, but also provides some normative data so they can interpret other patients' data," Caccese said. "We really don't know a lot about why people have persistent symptoms, and it seems to be very variable. So we're trying to understand this better to help predict who will have a prolonged recovery, and who will not."
https://www.sciencedaily.com/releases/2021/01/210122112323.htm
Deep sleep takes out the trash
January 20, 2021
Science Daily/Northwestern University
A new Northwestern University study reaffirms the importance of getting a good night's sleep.
By examining fruit flies' brain activity and behavior, the researchers found that deep sleep has an ancient, restorative power to clear waste from the brain. This waste potentially includes toxic proteins that may lead to neurodegenerative disease.
"Waste clearance could be important, in general, for maintaining brain health or for preventing neurogenerative disease," said Dr. Ravi Allada, senior author of the study. "Waste clearance may occur during wake and sleep but is substantially enhanced during deep sleep."
The study will publish tomorrow (Jan. 20) in the journal Science Advances.
Allada is the Edward C. Stuntz Distinguished Professor in Neuroscience and chair of the Department of Neurobiology in the Northwestern's Weinberg College of Arts and Sciences. He also is associate director of Northwestern's Center for Sleep and Circadian Biology. Bart van Alphen, a postdoctoral fellow in Allada's laboratory, was the paper's first author.
Although fruit flies seem very different from humans, the neurons that govern flies' sleep-wake cycles are strikingly similar to our own. For this reason, fruit flies have become a well-studied model organism for sleep, circadian rhythms and neurodegenerative diseases.
In the current study, Allada and his team examined proboscis extension sleep (PES), a deep-sleep stage in fruit flies, which is similar to deep, slow-wave sleep in humans. The researchers discovered that, during this stage, fruit flies repeatedly extend and retract their proboscis (or snout).
"This pumping motion moves fluids possibly to the fly version of the kidneys," Allada said. "Our study shows that this facilitates waste clearance and aids in injury recovery."
When Allada's team impaired flies' deep sleep, the flies were less able to clear an injected non-metabolizable dye from their systems and were more susceptible to traumatic injuries.
Allada said this study brings us closer to understanding the mystery of why all organisms need sleep. All animals -- especially those in the wild -- are incredibly vulnerable when they sleep. But research increasingly shows that the benefits of sleep -- including crucial waste removal -- outweigh this increased vulnerability.
"Our finding that deep sleep serves a role in waste clearance in the fruit fly indicates that waste clearance is an evolutionary conserved core function of sleep," the paper's coauthors write. "This suggests that waste clearance may have been a function of sleep in the common ancestor of flies and humans."
https://www.sciencedaily.com/releases/2021/01/210120151044.htm
Fragmented sleep patterns can predict vulnerability to chronic stress
January 13, 2021
Science Daily/New York University
New research from NYU Abu Dhabi's Laboratory of Neural Systems and Behavior for the first time used an animal model to demonstrate how abnormal sleep architecture can be a predictor of stress vulnerability. These important findings have the potential to inform the development of sleep tests that can help identify who may be susceptible -- or resilient -- to future stress.
In the study, Abnormal Sleep Signals Vulnerability to Chronic Social Defeat Stress, which appears in the journal Frontiers in Neuroscience, NYUAD Assistant Professor of Biology Dipesh Chaudhury and Research Associate Basma Radwan describe their development of a mouse model to detect how disruptions in Non-rapid Eye Movement (NREM) sleep result in increased vulnerability to future stress.
The researchers assessed the sleep characteristics of both stress-susceptible and stress-resilient mice before and after experiencing chronic social defeat (CSD) stress. The social behavior of the mice post-stress was classified in two main phenotypes: those susceptible to stress that displayed social avoidance and those that were resilient to stress. Pre-CSD, mice susceptible to stress displayed increased fragmentation of Non-Rapid Eye Movement (NREM) sleep due to increased switching between NREM and wake and shorter average duration of NREM bouts, relative to mice resilient to stress. Their analysis showed that the pre-CSD sleep features from both phenotypes of mice allowed prediction of susceptibility to stress with more than 80 percent accuracy. Post-CSD, susceptible mice maintained high NREM fragmentation during the light and dark phase while resilient mice exhibited high NREM fragmentation only in the dark.
The findings demonstrate that mice that become susceptible to CSD stress exhibit pre-existing abnormal sleep/wake characteristics prior to stress exposure. In addition, subsequent exposure to stress further impairs sleep and the homeostatic response.
"Our study is the first to provide an animal model to investigate the relationship between poor sleep continuity and vulnerability to chronic stress and depressive disorders," said Chaudhury and Radwan. "This marker of vulnerability to stress opens up avenues for many possible future studies that could further explain the underlying molecular processes and neural circuitry that lead to mood disorders."
https://www.sciencedaily.com/releases/2021/01/210112085407.htm
Study shows meaningful lockdown activity is more satisfying than busyness
January 11, 2021
Science Daily/RMIT University
New research shows people who pursue meaningful activities -- things they enjoy doing -- during lockdown feel more satisfied than those who simply keep themselves busy.
The study, published in PLOS ONE, shows you're better off doing what you love and adapting it to suit social distancing, like swapping your regular morning walk with friends for a zoom exercise session.
Simply increasing your level of activity by doing mindless busywork will leave you unsettled and unsatisfied.
Co-lead researcher Dr Lauren Saling from RMIT University in Melbourne, Australia said while novelty lockdown activities -- like baking or painting -- have their place, trying to continue what you enjoyed before lockdown can be more rewarding.
"Busyness might be distracting but it won't necessarily be fulfilling," she said.
"Rather, think about what activities you miss most and try and find a way of doing them."
Survey participants rated their level of wellbeing as it was during social distancing and retrospectively one month beforehand.
They also indicated how much time they spent engaged in various activities and nominated how important each activity was for them.
Although participants reported feeling more positive emotions while doing novelty 'meaningless' activities like binge watching TV, they also felt more negative emotions -- they felt unhappy just as much as they felt happy.
But when substituting activities enjoyed before lockdown -- like dining with friends -- for a virtual alternative, their positive and negative emotions were more subdued.
Saling said busyness riles you up, prompting you to change your behaviour, but meaningful activity -- doing what you enjoy -- calms you down.
"Extreme emotions are not necessarily a good thing," she said.
"Emotions are a mechanism to make you change your behaviour.
"But when you're doing what you love, it makes sense that you feel more balanced -- simply keeping busy isn't satisfying."
Saling said the study challenged assumptions that we are either happy or sad and that we can stave off sadness by keeping busy.
Rather, those who kept busy with mindless tasks felt more frustrated and even when they were happy felt less fulfilled.
"The study showed positive and negative affect worked together, not as opposites," Saling said.
"Respondents who simply stayed busy during lockdown reported an increase in both positive and negative emotions.
"This heightened emotionality will tend to shift you away from activity in general and towards meaningful activity."
The study also found the biggest change in positive emotions before and during lockdown was experienced by people aged under 40.
Saling said this was likely because it was harder for that age group to successfully substitute meaningful activities into a lockdown context.
https://www.sciencedaily.com/releases/2021/01/210111112126.htm
Heading outdoors keeps lockdown blues at bay
Study finds time spent outdoors is associated with higher levels of happiness
January 8, 2021
Science Daily/Anglia Ruskin University
A new study has found that spending time outdoors and switching off our devices is associated with higher levels of happiness during a period of COVID-19 restrictions.
Previous academic studies have indicated how being outdoors, particularly in green spaces, can improve mental health by promoting more positive body image, and lowering levels of depression and anxiety.
Jointly led by academics from Anglia Ruskin University (ARU) in the UK, the Karl Landsteiner University of Health Sciences in Austria, and Perdana University in Malaysia, this new research examined how levels of happiness during a national lockdown were affected by being outdoors, the amount of daily screen time (use of TV, computer and smartphone) and feelings of loneliness.
Using an experience sampling method (ESM), the researchers measured levels of happiness amongst a group of 286 adults three times a day, at random intervals, over a 21-day period. This allowed the participants to provide data in real-time rather than retrospectively, helping to avoid recall biases.
The research, published in the Journal of Happiness Studies, was carried out in April 2020, when the Austrian participants were allowed to leave their homes only for specific activities, which included exercise.
It found that levels of happiness were higher when participants were outdoors rather than indoors. In addition, more daily screen time and higher levels of loneliness were both associated with lower levels of happiness. The impact of loneliness on happiness was also weaker when participants were outdoors.
Co-lead author Viren Swami, Professor of Social Psychology at Anglia Ruskin University (ARU), said: "While lockdowns can help slow down the transmission of COVID-19, research has also shown that prolonged periods of lockdown take their toll on mental health.
"Our results are important in this context because they show that being able to spend time outdoors under conditions of lockdown has a beneficial impact on psychological wellbeing. Being outdoors provides opportunities to escape from the stresses of being confined at home, maintain social relationships with others, and engage in physical activity -- all of which can improve mental health.
"Our findings have practical health policy implications. Given that further lockdown restrictions have now become necessary in the UK, public health messages that promote getting some fresh air instead of staying indoors and staring at our screens could really help to lift people's mood this winter."
https://www.sciencedaily.com/releases/2021/01/210108084121.htm
Increase in pleasurable effects of alcohol over time can predict alcohol use disorder
New research challenges existing dogma that higher tolerance for stimulating and rewarding effects of alcohol leads to addiction
January 5, 2021
Science Daily/University of Chicago Medical Center
A new study out of the University of Chicago Medicine following young adult drinkers for 10 years has found that individuals who reported the highest sensitivity to alcohol's pleasurable and rewarding effects at the start of the trial were more likely to develop an alcohol use disorder (AUD) over the course of the study.
Moreover, when retested on their responses 10 years later, those who became alcoholics had the highest levels of alcohol stimulation, liking and wanting -- and these were heightened compared to their baseline with no signs of tolerance to these pleasurable effects.
The research, published on Jan. 5 in the American Journal of Psychiatry, followed a cohort of 190 young adults in a laboratory-based binge-drinking scenario at three regular intervals over the course of 10 years.
These results indicate that individuals developing an AUD are more likely to be sensitized to the effects of alcohol -- that is, they experience a stronger positive response -- rather than habituated to the substance with a lower level of response. In these same individuals, alcohol was less sedating for them from the beginning and this did not change over time.
"Prior longitudinal studies have looked at young drinkers' response to alcohol and focused primarily on the fatiguing and impairing effects of alcohol," said lead author Andrea King, PhD, professor of psychiatry and behavioral neuroscience at UChicago Medicine. "The thinking that alcoholics do not like the effects of alcohol over time is based on ad-hoc reports of patients entering treatment. Only by testing the same people over a substantial amount of time to see if alcohol responses change over time were we able to observe this elevated response to alcohol compared with placebo, and in participants who did not know the contents of the drinks, so expectancy effects were minimized."
The study showed that higher sensitivity to the euphoric and rewarding effects of alcohol can predict who will go on to have an AUD as they progress through their 20s and 30s.
"These pleasurable alcohol effects grow in intensity over time, and do not dissipate, in people progressing in excessive drinking," said King. "This tells us that having a higher sensitivity to the rewarding effects of alcohol in the brain puts such individuals at higher risk for developing addiction. It all fits a picture of persistent pleasure-seeking that increases the likelihood of habitual excessive drinking over time. Alcoholics were thought to need to drink more to finally get their desired effect when they drink, but these well-controlled data do not support that contention. They get the desirable alcohol effect early in the drinking bout and that seems to fuel wanting more alcohol."
While it may seem relatively intuitive that individuals who experience alcohol's pleasurable effects most intensely are at the greatest risk for developing drinking problems, King's findings run counter to current prominent addiction theories.
"Our results support a theory called incentive-sensitization," said King. "In response to a standard intoxicating dose of alcohol in the laboratory, ratings of wanting more alcohol increased substantially over the decade among the individuals who developed more severe AUD. Additionally, the hedonic response -- essentially, how much a person liked the effects -- remained elevated over this interval and didn't go down at all. This has traditionally been the crux of the lore of addiction -- that addicts don't like the drug (alcohol) but can't stop using it."
The participants were regular light or heavy social drinkers in their mid-20s at the start of the trial from 2004 to 2006. They were brought back for repeated testing of alcohol responses in the laboratory five and 10 years later as they approached middle adulthood. In between testing periods, participants were interviewed at near-annual intervals to track their drinking patterns and symptoms of AUD over time.
King hopes that these results can help improve our understanding of how some individuals have more vulnerability to developing AUD, while others remain social drinkers over their lifespan. She also points out that the results can help to develop better treatments for AUDs and inform earlier interventions for individuals who may be at high risk for developing an addiction.
"I'm already using this information to inform how I talk about addiction with my therapy clients," King said. "It can be frustrating for them to see other people who can have a couple drinks and just stop there. They can't understand why they repeatedly seem unable to do that, too, and I tell them, it may be because your brain responds differently to alcohol that makes it harder to stop drinking once you start. Knowing that information can empower a person to make different decisions. Even with our current pandemic, a person may drink to cope with stress or reduce negative feelings, but that doesn't mean that they don't also experience the buzz, or pleasurable effects from drinking. This is most concerning for at-risk drinkers as those responses may intensify as they progress with heavier drinking."
Based on this research, King sees the potential for a sort of "personalized medicine" approach for treating AUDs, describing how sharing an individual's "thumbprint" response to alcohol can make a difference in how they think about their consumption.
"This could be an opportunity for early intervention, comparable to how someone may get their cholesterol tested and then may be more motivated to change their diet, exercise more or start a medication to rein it in," King said. "Similarly, knowing one's acute response to alcohol and how it may indicate a person's future risk for drinking problems, one may decide to change their drinking on their own or seek help to avoid the progression to addiction."
https://www.sciencedaily.com/releases/2021/01/210105084649.htm
Difference in blood pressure between arms linked to greater early death risk
December 21, 2020
Science Daily/University of Exeter
Robust evidence from a large international study confirms that a difference in blood pressure readings between arms is linked to greater risk of heart attack, stroke and death.
Led by the University of Exeter, the global INTERPRESS-IPD Collaboration conducted a meta-analysis of all the available research, then merged data from 24 global studies to create a database of nearly 54,000 people. The data spanned adults from Europe, the US, Africa and Asia for whom blood pressure readings for both arms were available.
Funded by the National Institute for Health Research (NIHR) and published today in Hypertension, the study is the first to conclude that the greater the inter-arm blood pressure difference, the greater the patient's additional health risk.
Currently, international blood pressure guidelines advise health professionals to measure blood pressure in both arms when assessing cardiovascular risk,- yet this is widely ignored. The new study provides a new upper limit of 'normal' for an inter-arm difference in blood pressure, which is significantly lower than the current guidance. The research could lead to a change in international hypertension guidelines, meaning more at-risk patients could be identified and receive potentially life-saving treatment.
In a methodology that put patients at its heart, working with a patient advisory group at every step of the research, the team analysed data on inter-arm blood pressure difference, and tracked the number of deaths, heart attacks and strokes that occurred in the cohort over 10 years.
Lead author and GP Dr Chris Clark, of the University of Exeter Medical School, said: "Checking one arm then the other with a routinely used blood pressure monitor is cheap and can be carried out in any healthcare setting, without the need for additional or expensive equipment. Whilst international guidelines currently recommend that this is done, it only happens around half of the time at best, usually due to time constraints. Our research shows that the little extra time it takes to measure both arms could ultimately save lives."
"We've long known that a difference in blood pressure between the two arms is linked to poorer health outcomes. The large numbers involved in the INTERPRESS-IPD study help us to understand this in more detail. It tells us that the higher the difference in blood pressure between arms, the greater the cardiovascular risk, so it really is critical to measure both arms to establish which patients may be at significantly increased risk. Patients who require a blood pressure check should now expect that it's checked in both arms, at least once."
Blood pressure rises and falls in a cycle with each pulse. It is measured in units of millimetres of mercury (mmHg), and the reading is always given as two numbers: the upper (systolic) reading represents the maximum blood pressure and the lower (diastolic) value is the minimum blood pressure. A high systolic blood pressure indicates hypertension. This affects one third of the adult population and is the single leading cause globally of preventable heart attacks, strokes and deaths. A significant difference between the systolic blood pressure measurements in the two arms could be indicative of a narrowing, or a stiffening, of the arteries, which can affect blood flow. These arterial changes are recognised as a further risk marker for subsequent heart attack, stroke or early death, and should be investigated for treatment.
The researchers concluded that each mmHg difference found between the two arms, elevated predicted 10-year risk of one of the following occurring by one percent; new angina, a heart attack or stroke.
At the moment, both UK and European guidelines recognise a systolic difference of 15 mmHg or more between the two arms as the threshold indicative of additional cardiovascular risk. This new study found that a lower threshold of 10 mmHg was clearly indicative of additional risk, which would mean that far more people should be considered for treatment if such a difference between arms is present. To this end, the research team has created a tool that is easy for clinicians to use, to establish who should be considered for treatment based on their risk, incorporating the blood pressure reading in both arms.
Research co-author Professor Victor Aboyans, head of the department of cardiology at the Dupuytren University Hospital in Limoges, France, said "We believe that a 10 mmHg difference can now reasonably be regarded as an upper limit of normal for systolic inter-arm blood pressure, when both arms are measured in sequence during routine clinical appointments. This information should be incorporated into future guidelines and clinical practice in assessing cardiovascular risk. It would mean many more people were considered for treatment that could reduce their risk of heart attack, stroke and death."
An interarm difference of greater than 10 mmHg occurs in 11 per cent of people with high blood pressure (hypertension) -- itself a known health risk -- and in four per cent of the general population.
https://www.sciencedaily.com/releases/2020/12/201221101208.htm
How hope can make you happier with your lot in life
December 16, 2020
Science Daily/University of East Anglia
Having hope for the future could protect people from risky behaviours such as drinking and gambling -- according to new research from the University of East Anglia.
Researchers studied 'relative deprivation' -- the feeling that other people have things better than you in life.
They wanted to find out why only some people experiencing this turn to escapist and risky behaviours such as drinking alcohol, taking drugs, over-eating or gambling, while others do not.
And they found that the answer lies in hope.
Postgraduate researcher Shahriar Keshavarz, from UEA's School of Psychology, said: "I think most people have experienced relative deprivation at some point in their lives. It's that feeling of being unhappy with your lot, the belief that your situation is worse than others, that other people are doing better than you.
"Roosevelt famously said that 'comparison is the thief of joy'. It's that feeling you have when a friend buys a new car, or your sister gets married, or a colleague finds a better job or has a better income.
"Relative deprivation can trigger negative emotions like anger and resentment, and it has been associated with poor coping strategies like risk taking, drinking, taking drugs or gambling.
"But not everyone scoring high on measures of relative deprivation makes these poor life choices. We wanted to find out why some people seem to cope better, or even use the experience to their advantage to improve their own situation.
"There is a lot of evidence to show that remaining hopeful in the face of adversity can be advantageous, so we wanted to see if hope can help people feel happier with their lot and buffer against risky behaviours."
The research team carried out two lab-based experiments with 55 volunteers. The volunteers were quizzed to find out how much they feel relative deprivation and hope.
The researchers also induced feelings of relative deprivation in the volunteers, by telling them how deprived they were compared to their peers, based on a questionnaire about their family income, age and gender.
They then took part in specially designed gambling games that involved risk-taking and placing bets with a chance to win real money.
Dr Piers Fleming, also from UEA's School of Psychology, said: "The aim of this part of the study was to see whether feeling relatively deprived -- elicited by the knowledge that one has less income than similar others -- causes greater risk-taking among low-hopers and decreased risk-taking among high-hopers.
"We looked at the people who scored high for relative deprivation, the ones that thought their situation in life was worse than those around them. And we looked at those who also scored high for hope.
"We found that the volunteers who scored high for hope, were much less likely to take risks in the game. Those who weren't too hopeful, were a lot more likely to take risks."
Another experiment looked at whether hope helped people in the real world. They worked with 122 volunteers who had gambled at least once in the last year. The volunteers took part in questionnaires to gauge how hopeful they are, whether they feel relatively deprived and to measure problem gambling.
Of the participants, 33 had no gambling problems (27 per cent), 32 had low level of problems (26 per cent), 46 had moderate level of problems leading to some negative consequences (38 per cent) and 11 were problem gamblers with a possible loss of control (9 per cent).
Mr Keshavarz said: "When we looked at these scores compared to scores for hope and relative deprivation, we found that increased hope was associated with a decreased likelihood of losing control of gambling behaviour -- even in those who experienced relative deprivation.
"Interestingly, our study found no significant relation between hope and gambling severity among relatively privileged persons. We don't know why this is, but it could be that they are gambling recreationally or better able to stop when the fun stops."
The research team say that nurturing hope in people who are unhappy with their lot could protect against harmful behaviours like drinking and gambling.
https://www.sciencedaily.com/releases/2020/12/201216104631.htm
Three pillars of mental health: Good sleep, exercise, raw fruits and veggies
December 16, 2020
Science Daily/University of Otago
Getting good quality sleep, exercising, and eating more raw fruits and vegetables predicts better mental health and well-being in young adults, a University of Otago study has found.
The study, published in Frontiers in Psychology, surveyed more than 1100 young adults from New Zealand and the United States about their sleep, physical activity, diet, and mental health.
Lead author Shay-Ruby Wickham, who completed the study as part of her Master of Science, says the research team found sleep quality, rather than sleep quantity, was the strongest predictor of mental health and well-being.
"This is surprising because sleep recommendations predominantly focus on quantity rather than quality. While we did see that both too little sleep -- less than eight hours -- and too much sleep -- more than 12 hours -- were associated with higher depressive symptoms and lower well-being, sleep quality significantly outranked sleep quantity in predicting mental health and well-being.
"This suggests that sleep quality should be promoted alongside sleep quantity as tools for improving mental health and well-being within young adults," Ms Wickham says.
Along with quality sleep, exercising, and eating more raw fruits and vegetables -- in that order -- were three modifiable behaviours which correlated with better mental health and well-being in young adults.
Depressive symptoms were lowest for young adults who slept 9.7 hours per night, and feelings of well-being were highest for those who slept 8 hours per night.
Well-being was highest for young adults who ate 4.8 servings of raw fruit and vegetables per day; those who ate less than two servings, and also more than eight servings, reported lower feelings of well-being.
"Sleep, physical activity, and a healthy diet can be thought of as three pillars of health, which could contribute to promoting optimal well-being among young adults, a population where the prevalence of mental disorders is high and well-being is suboptimal," Ms Wickham says.
Senior author, Associate Professor Tamlin Conner, of the Department of Psychology, says most prior research examines these health behaviours in isolation of each other.
"We showed that they are all important for predicting which young adults are flourishing versus suffering."
She also stressed the study's findings were correlations only.
"We didn't manipulate sleep, activity, or diet to test their changes on mental health and well-being. Other research has done that and has found positive benefits. Our research suggests that a 'whole health' intervention prioritising sleep, exercise, and fruit and vegetable intake together, could be the next logical step in this research," she says.
https://www.sciencedaily.com/releases/2020/12/201216094647.htm
New insights about depression
Researchers find links between inflammation, menopause, and depressive disorder
December 14, 2020
Science Daily/UT Southwestern Medical Center
Recently published UT Southwestern research reveals new insights about risk factors for depression based on data from a landmark longitudinal study focused on heart disease.
One study, published in the Journal of Clinical Psychiatry, shows a link between an inflammatory molecule in the blood and a person's likelihood of depressive symptoms. The other study, in the journal Maturitas, indicates which symptoms of menopause are most predictive of depression.
Both studies are based on data from the Dallas Heart Study (DHS), which since 2000 has tracked the health of thousands of participants with the goal of improving the diagnosis, prevention, and treatment of heart disease.
"The DHS dataset is an extraordinary resource at UT Southwestern," says Sherwood Brown, M.D., Ph.D., senior author of both papers and professor of psychiatry and vice chair for clinical research at UTSW.
The first two years of the study, more than 6,000 residents of Dallas County completed a detailed medical survey; 3,500 of them, aged 30 to 65, provided blood samples and underwent imaging studies. The DHS put particular emphasis on recruiting a diverse group; more than half of all participants were African American and 17 percent were Hispanic.
In the process of collecting information, data useful for studying other medical conditions was amassed. Brown immediately saw the utility for the DHS data in his own work on depression.
Inflammation and depression
Depression is estimated to affect 4.4 percent of the world's population, making it one of the leading causes of disability. Researchers have struggled to understand all the molecular changes in the body that accompany major depressive disorder. More than 20 years ago, clinicians found that a pro-inflammatory drug used to treat some diseases could cause depression. Since that time, researchers including Brown have wondered about the link between inflammatory molecules and depression.
To that end, Brown and Samara Huckvale -- an undergraduate at Columbia University who as a high school student worked in Brown's lab in 2019 through UT Southwestern's STARS (Science Teacher Access to Resources at Southwestern) Summer Research Program -- analyzed data on 3,033 adults who had provided blood samples and completed a depression screening questionnaire as part of the DHS. The STARS Program, begun in 1991, provides summer research opportunities to high school students.
They discovered that levels of GlycA, an inflammatory molecule that's not routinely tested for in patients, correlated with the severity of depressive symptoms. Even after controlling for factors such as sex, ethnicity, antidepressant use, education, and body mass index, GlycA levels remained associated with depression severity.
"This study suggests that maybe we could predict or diagnose depression based on inflammatory scores," says Huckvale, who aspires to be a chemist. "Or maybe eventually we'll be able to design therapies that actually target this inflammation to treat depression."
Brown, who holds the Lou and Ellen McGinley Distinguished Chair in Psychiatric Research and the Aradine S. Ard Chair in Brain Science, adds that he'd like to study whether GlycA levels can predict how well a treatment for depression works or help guide the best antidepressants for particular patients. He'd also like to follow patients over time to gauge whether GlycA levels rise before or after the onset of depression symptoms.
Menopause and depression
In the Maturitas paper, Brown and his colleagues used DHS data to study menopausal women, a group known to have an increased risk of depression.
Previous studies have found a correlation between the most common symptoms of menopause -- hot flashes, night sweats, and sleep disturbances -- and the onset of depression. Menopause also causes sexual symptoms, including vaginal dryness and low libido, but few studies have looked at the association between these symptoms and depression.
In the study, Brown and colleagues analyzed DHS data on 384 women aged 37 to 73 years old who self-reported being in menopause. Sixty-four percent of the women were non-Hispanic Black, 26.8 percent were non-Hispanic white, and 9.11 percent were Hispanic.
"There are very different cultural and ethnic experiences around menopause, so it was important to us to look at a very diverse sample of women," says Michael Xincheng Ji, co-first author of the study and a fourth-year UTSW medical student.
As part of the Dallas Heart Study, the women reported whether they had symptoms classically associated with menopause, which the researchers grouped into vasomotor, psychosocial, physical, or sexual symptoms. In addition, each woman completed the Quick Inventory of Depressive Symptomatology-Self Report survey (QIDS-SR), which gauged the presence of depression symptoms.
The prevalence of sexual symptoms of menopause was positively associated with a higher score on the QIDS-SR. This association remained even after excluding women who were taking antidepressants, and there was also an association between psychosocial symptoms of menopause and the QIDS-SR score. No association was found between vasomotor or physical symptoms and the QIDS-SR score, and ethnicity was not a strong predictor of the depression symptoms.
"Recognizing patterns in who is most likely to develop depression is really important to help guide our screening efforts," says Sydney Singleterry, co-first author of the new work and a fourth-year UTSW medical student.
"What we hope is that these findings make clinicians think about the possibility of depression when they hear a woman reporting these symptoms," says Brown, also a member of the Peter O'Donnell Jr. Brain Institute.
https://www.sciencedaily.com/releases/2020/12/201214150337.htm
The power of validation in helping people stay positive
Supporting someone's negative emotions can help foster a positive outlook
December 14, 2020
Science Daily/Ohio State University
Telling a distressed friend or family member something as simple as "I understand why you feel that way" can go a long way toward helping loved ones feel better, new research suggests.
In the study, participants described to the researchers a real-life incident that made them angry.
When researchers didn't show support or understanding for the anger participants were describing, the story-tellers showed declines in positive emotions. But when the researchers validated what the participants were saying, their positive emotions were protected and stayed the same.
Similarly, study participants reported dips in their overall mood as they recalled the anger-provoking event, and only those who were validated reported a recovery of mood back to their starting point.
There was no significant difference found in participants' negative emotions -- a result that speaks to the value of focusing on protecting positivity, said Jennifer Cheavens, senior author of the study and a professor of psychology at The Ohio State University.
"We have underestimated the power of positive emotions. We spend so much time thinking about how to remedy negative emotions, but we don't spend much time thinking about helping people harness and nurture positive emotions," Cheavens said.
"It's really important to help people with their depression, anxiety and fear, but it's also important to help people tap into curiosity, love, flexibility and optimism. People can feel sad and overwhelmed, and also hopeful and curious, in the same general time frame."
The study is published online in the Journal of Positive Psychology.
In three experiments, the researchers assessed the effects of validation and invalidation on what are known clinically as positive and negative affect. Positive affect refers to positive emotions and expression that Cheavens said allow us to be curious, connected and flexible in our thinking. Negative affect, on the other hand, refers to negative emotions and expression ranging from disgust to fear to sadness.
A total of 307 undergraduate students participated in the experiments. The students completed questionnaires measuring positive and negative affect at the beginning and end of the study and overall mood at several time points during the experiments.
Researchers asked participants to think and write for five minutes about a time when they felt intense anger, and then verbally describe those experiences to a researcher. Based on randomized assignments, the experimenter either validated or invalidated their angry feelings.
The participants' experiences with anger covered a wide range: roommate troubles, unfaithful romantic partners, being the victim of a theft or getting mad at their parents.
Experimenters listening to their stories used flexible scripts to respond. Validating comments included such phrases as "Of course you'd be angry about that" or "I hear what you're saying and I understand you feel angry."
Invalidating responses ranged from "That doesn't sound like anger" to "Why would that make you so angry?"
Results showed that all participants had a decrease in positive affect while they were thinking and writing about being angry. However, when they started describing the situation to experimenters, the validated participants' positive affect matched or even exceeded their baseline measures. The positive affect scores for those who were invalidated did not recover while talking with the experimenters.
Based on five measures of mood in two of the three studies, participants' mood consistently darkened as they considered what made them angry. Validated participants' moods were restored to normal, but the invalidated students' moods generally continued to get worse.
The research team conducted the studies with plans to apply the results in a therapy setting. But the findings are relevant for relationships as well, Cheavens said.
"When you process negative emotions, that negative affect gets turned on. But if someone validates you, it keeps your positive affect buffered. Validation protects people's affect so they can stay curious in interpersonal interactions and in therapy," she said.
"Adding validation into therapy helps people feel understood, and when we feel understood we can receive feedback on how we also might change. But it's not a uniquely clinical thing -- often the same ways you make therapy better are ways you make parenting, friendships and romantic relationships better.
https://www.sciencedaily.com/releases/2020/12/201214123517.htm
Gut microbiota plays a role in brain function and mood regulation
December 11, 2020
Science Daily/Institut Pasteur
Depression is a mental disorder that affects more than 264 million people of all ages worldwide. Understanding its mechanisms is vital for the development of effective therapeutic strategies. Scientists from the Institut Pasteur, Inserm and the CNRS recently conducted a study showing that an imbalance in the gut bacterial community can cause a reduction in some metabolites, resulting in depressive-like behaviors. These findings, which show that a healthy gut microbiota contributes to normal brain function, were published in Nature Communications on December 11, 2020.
The bacterial population in the gut, known as the gut microbiota, is the largest reservoir of bacteria in the body. Research has increasingly shown that the host and the gut microbiota are an excellent example of systems with mutually beneficial interactions. Recent observations also revealed a link between mood disorders and damage to the gut microbiota. This was demonstrated by a consortium of scientists from the Institut Pasteur, the CNRS and Inserm, who identified a correlation between the gut microbiota and the efficacy of fluoxetine, a molecule frequently used as an antidepressant. But some of the mechanisms governing depression, the leading cause of disability worldwide, remained unknown.
Using animal models, scientists recently discovered that a change to the gut microbiota brought about by chronic stress can lead to depressive-like behaviors, in particular by causing a reduction in lipid metabolites (small molecules resulting from metabolism) in the blood and the brain.
These lipid metabolites, known as endogenous cannabinoids (or endocannabinoids), coordinate a communication system in the body which is significantly hindered by the reduction in metabolites. Gut microbiota plays a role in brain function and mood regulation
Endocannabinoids bind to receptors that are also the main target of THC, the most widely known active component of cannabis. The scientists discovered that an absence of endocannabinoids in the hippocampus, a key brain region involved in the formation of memories and emotions, resulted in depressive-like behaviors.
The scientists obtained these results by studying the microbiotas of healthy animals and animals with mood disorders. As Pierre-Marie Lledo, Head of the Perception and Memory Unit at the Institut Pasteur (CNRS/Institut Pasteur) and joint last author of the study, explains: "Surprisingly, simply transferring the microbiota from an animal with mood disorders to an animal in good health was enough to bring about biochemical changes and confer depressive-like behaviors in the latter."
The scientists identified some bacterial species that are significantly reduced in animals with mood disorders. They then demonstrated that an oral treatment with the same bacteria restored normal levels of lipid derivatives, thereby alleviating the depressive-like behaviors. These bacteria could therefore serve as an antidepressant. Such treatments are known as "psychobiotics."
"This discovery shows the role played by the gut microbiota in normal brain function," continues Gérard Eberl, Head of the Microenvironment and Immunity Unit (Institut Pasteur/Inserm) and joint last author of the study. If there is an imbalance in the gut bacterial community, some lipids that are vital for brain function disappear, encouraging the emergence of depressive-like behaviors. In this particular case, the use of specific bacteria could be a promising method for restoring a healthy microbiota and treating mood disorders more effectively.
https://www.sciencedaily.com/releases/2020/12/201211115507.htm
Biological diversity evokes happiness
More bird species in their vicinity increase life satisfaction of Europeans as much as higher income
December 4, 2020
Science Daily/German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
A high biodiversity in our vicinity is as important for life satisfaction as our income, scientists found. All across Europe, the individual enjoyment of life correlates with the number of surrounding bird species. An additional 10% of bird species therefore increases the Europeans' life satisfaction as much as a comparable increase in income. Nature conservation thus constitutes an investment in human well-being.
Under the current pandemic conditions, activities out in nature are a popular pastime. The beneficial effects of a diverse nature on people's mental health have already been documented by studies on a smaller scale. Scientists of the Senckenberg Gesellschaft für Naturforschung, the iDiv, and the University of Kiel now examined for the first time whether a diverse nature also increases human well-being on a Europe- wide scale.
To this end, the researchers used the data from the "2012 European quality of Life Survey" to study the connection between the species diversity in their surroundings and the life satisfaction in more than 26,000 adults from 26 European countries. Species diversity was measured based on the diversity of avian species, as documented in the European breeding bird atlas.
"Europeans are particularly satisfied with their lives if their immediate surroundings host a high species diversity," explains the study's lead author, Joel Methorst, a doctoral researcher at the Senckenberg Biodiversity and Climate Research Centre, the iDiv, and the Goethe University in Frankfurt. "According to our findings, the happiest Europeans are those who can experience numerous different bird species in their daily life, or who live in near-natural surroundings that are home to many species."
Birds are well-suited as indicators of biological diversity, since they are among the most visible elements of the animate nature -- particularly in urban areas. Moreover, their song can often be heard even if the bird itself is not visible, and most birds are popular and people like to watch them. But there is also a second aspect that affects life satisfaction: the surroundings. A particularly high number of bird species can be found in areas with a high proportion of near-natural and diverse landscapes that hold numerous greenspaces and bodies of water.
"We also examined the socio-economic data of the people that were surveyed, and, much to our surprise, we found that avian diversity is as important for their life satisfaction as is their income," explains Prof. Dr. Katrin Böhning-Gaese, director of the Senckenberg Biodiversity and Climate Research Centre, professor at the Goethe University in Frankfurt am Main, and member of the iDiv. This result becomes particularly obvious when both values increase by ten percent. Fourteen additional bird species in the vicinity raise the level of life satisfaction at least as much as an extra 124 Euros per month in the household account, based on an average income of 1,237 Euro per month in Europe.
According to the study, a diverse nature therefore plays an important role for human well-being across Europe -- even beyond its material services. At the same time, the researchers draw attention to impending health-related problems. "The Global Assessment 2019 by the World Biodiversity Council IPBES and studies of avian species in agricultural landscapes in Europe clearly show that the biological diversity is currently undergoing a dramatic decline. This poses the risk that human well-being will also suffer from an impoverished nature. Nature conservation therefore not only ensures our material basis of life, but it also constitutes an investment in the well-being of us all," adds Methorst in conclusion.
https://www.sciencedaily.com/releases/2020/12/201204110246.htm
Drinking linked to a decline in brain health from cradle to grave
December 3, 2020
Science Daily/BMJ
The evidence for the harmful effects of alcohol on brain health is compelling, but now experts have pin-pointed three key time periods in life when the effects of alcohol are likely to be at their greatest.
Writing in The BMJ today, researchers in Australia and the UK say evidence suggests three periods of dynamic brain changes that may be particularly sensitive to the harmful effects of alcohol: gestation (from conception to birth), later adolescence (15-19 years), and older adulthood (over 65 years).
They warn that these key periods "could increase sensitivity to the effects of environmental exposures such as alcohol" and say harm prevention policies "must take the long view."
Globally, around 10% of pregnant women consume alcohol, with the rates considerably higher in European countries than the global average, they write.
Heavy alcohol use during pregnancy can cause fetal alcohol spectrum disorder, associated with widespread reductions in brain volume and cognitive impairment. But data suggest that even low or moderate alcohol consumption during pregnancy is significantly associated with poorer psychological and behavioural outcomes in offspring.
In terms of adolescence, more than 20% of 15-19 year olds in European and other high income countries report at least occasional binge drinking (defined as 60 g of ethanol on a single occasion), they add.
Studies indicate that the transition to binge drinking in adolescence is associated with reduced brain volume, poorer white matter development (critical for efficient brain functioning), and small to moderate deficits in a range of cognitive functions.
And in older people, alcohol use disorders were recently shown to be one of the strongest modifiable risk factors for all types of dementia (particularly early onset) compared with other established risk factors such as high blood pressure and smoking.
Although alcohol use disorders are relatively rare in older adults, the authors point out that even moderate drinking has been shown to be linked to a small but significant loss of brain volume in midlife, although further studies are needed to test whether these structural changes translate into functional impairment.
Furthermore, demographic trends may compound the effect of alcohol use on brain health, they write. For example, women are now just as likely as men to drink alcohol and experience alcohol related harms, and global consumption is forecast to rise further in the next decade.
The effects of the covid-19 pandemic on alcohol use and related harms are unclear, but alcohol use increased in the long term after other major public health crises, they add.
As such, they call for an integrated approach to harm reduction at all ages.
"Population based interventions such as guidelines on low risk drinking, alcohol pricing policies, and lower drink driving limits need to be accompanied by the development of training and care pathways that consider the human brain at risk throughout life," they conclude.
https://www.sciencedaily.com/releases/2020/12/201203200605.htm
Researchers find how stress and the circadian clock affect sleep
The findings could lead to the development of new therapies for sleep disorders caused by stress or a disturbed circadian rhythm
November 30, 2020
Science Daily/Nagoya University
A Nagoya University-led research team in Japan has found a new neural pathway that links the circadian clock, stress, and wakefulness in mammals. The team identified a neuron, called the corticotropin-releasing factor (CRF) neuron, that becomes excessively active when the mammal is under stress, which could trigger insomnia and other sleep disorders. Their findings were recently published in the journal Science Advances.
Living organisms exhibit a 24-hour oscillation called the circadian rhythm. In mammals, the central circadian clock, located in the brain's suprachiasmatic nucleus (SCN) neurons, regulates the sleep-wake cycle. However, in the event of life-threatening situations, the circadian rhythm signal is shut off to keep the animal awake so that it can escape from danger even when it would normally be time to sleep. Although the temporary shutoff of the sleep-wake cycle is necessary for survival, excessive or prolonged stress caused by such dangers can trigger insomnia and other sleep disorders.
"It is well-known that the circadian clock and stress have an effect on sleep, but it was unclear which neural pathway is crucial for the circadian regulation of sleep and wakefulness," says Dr. Daisuke Ono of the Research Institute of Environmental Medicine at Nagoya University. To determine the pathway, a Nagoya University research team led by Prof. Akihiro Yamanaka and Dr. Ono, in collaboration with Takashi Sugiyama at Olympus Corporation in Japan, conducted a study using mice.
The researchers focused on CRF neurons -- which are known to play a role in stress response -- that are located in the paraventricular nucleus of the hypothalamus. They investigated how sleep and wakefulness in mice would be affected when the CRF neurons were activated. The results showed that the activated CRF neurons kept the animals awake and made them move around vigorously, indicating that their wakefulness was promoted. The researchers also observed that CRF neurons remained active when the mice were awake, and that when the neurons' activity was suppressed, the animals' wakefulness and locomotor activities were reduced.
Further investigations also showed that inhibitory neurons in the SCN, called GABAergic neurons, play a significant role in regulating the activity of CRF neurons, and that the activation of CRF neurons stimulates orexin neurons in the lateral hypothalamus, which results in the promotion of wakefulness.
The team thus concluded that GABAergic neurons in the SCN control the activity of CRF neurons, which ultimately regulates the sleep-wake cycle. "We identified this neural pathway in mice, which are nocturnal animals. Further studies are required to elucidate how the nocturnal and diurnal difference is regulated in the brain," says Dr. Ono.
"In today's society, sleep disorders are a serious problem. We hope our finding will contribute to the development of new therapies for insomnia and other sleep disorders caused by stress or a disturbed circadian rhythm."
https://www.sciencedaily.com/releases/2020/11/201130113534.htm