Remember the first time you...? Mysterious brain structure sheds light on addiction
Cocaine-addicted mice shed light on claustrum's role in associating reward with context
July 23, 2020
Science Daily/The Hebrew University of Jerusalem
Do you remember where you were when you first heard that two planes had crashed into New York's Twin Towers? Or where you had your first kiss? Our brains are wired to retain information that relates to the context in which highly significant events occurred. This mechanism also underlies drug addiction and is the reason why hanging out in an environment or with people associated with memories of drug use often leads to relapse.
How our brains create this strong association, however, is less clear. Now, new research by Professor Ami Citri and PhD student Anna Terem at Hebrew University of Jerusalem (HU)'s Edmond and Lily Safra Center for Brain Sciences and the Alexander Silberman Institute of Life Science, shows that a relatively obscure brain region known as the claustrum plays a significant role in making these connections. They published their findings in the latest edition of Current Biology.
The researchers' findings fit the idea of "incentive salience," the process that determines the desirability of an otherwise neutral stimulus. For example, a candy store façade becomes very attractive to kids after repeated associations with the rewarding treats that lie within. In time, children unconsciously learn to "want" to see the store stimulus, which is separate from their "liking" the actual candy reward. Taking a closer look at how context becomes associated with cocaine, the researchers found a group of neurons within the claustrum that lit up during cocaine use. Further, these neurons are pivotal in the formation of an incentive salience that links context with the pleasure of cocaine.
To determine when and how the claustrum participates in incentive salience, Citri and his team employed a conditioned-place preference (CPP) test for a group of lab mice. During this test, the mice learned to associate reward with context. The researcher administered cocaine to the mice and placed them in an area with distinctive flooring (rugged) and wall patterns (dots), ones that a mouse would notice, as the drug started to kick in. After a few times of this, when placed in a room where the mice could choose either to hang out in a region similar to the one paired with cocaine (rugged floors and dots wall) or a neutral area (smooth floor and striped walls), the mice would quickly congregate in the area where their drug high had played out.
To test the claustrum's involvement in how a context becomes associated with a given reward, Citri and his team observed the changes in mice behavior when they inhibited these claustral neurons. They found that the inhibition of these neurons inhibited the mice's behavioral responses to cocaine, meaning they no longer preferred hanging out in the cocaine-paired environment. On the other hand, activating these neurons -- even in the absence of any cocaine -- caused the mice to develop a preference for this context.
Importantly, the team found that the activity of the claustrum was not necessary for retrieval of the cocaine memory. Once the mice had been placed in a cocaine-paired context several times to enjoy their cocaine high, the memory for this context was encoded and inhibition of the claustrum had no effect on their preference for the cocaine-paired context. "These findings boosted our confidence that the claustrum is indeed integral to incentive salience, heightening the awareness of the mouse to the context in which it experienced the drug high" shared Citri.
As the number of deaths caused by drug overdose increases from year to year, this new study has wide-ranging implications towards a better understanding of the nature of addiction and the importance of breaking contextual cues before they develop. "By recognizing that the claustrum plays a pivotal role in creating a context association for reward, it becomes a structure of interest for the field of addiction. We hope this knowledge will lead to the development of new diagnostic tools to identify populations susceptible to addiction, as well as new therapeutic approaches," concluded Terem.
https://www.sciencedaily.com/releases/2020/07/200723115904.htm
When it comes to happiness, what's love got to do with it?
July 23, 2020
Science Daily/Michigan State University
How accurate was William Shakespeare when he said, "'Tis better to have loved and lost than never to have loved at all"? Researchers from Michigan State University conducted one of the first studies of its kind to quantify the happiness of married, formerly married and single people at the end of their lives to find out just how much love and marriage played into overall well-being.
The study -- published in the Journal of Positive Psychology -- examined the relationship histories of 7,532 people followed from ages 18 to 60 to determine who reported to be happiest at the end of their lives.
"People often think that they need to be married to be happy, so we asked the questions, 'Do people need to be in a relationship to be happy? Does living single your whole life translate to unhappiness? What about if you were married at some point but it didn't work out?,'" said William Chopik, MSU assistant professor of psychology and co-author of the paper. "Turns out, staking your happiness on being married isn't a sure bet."
Chopik and Mariah Purol, MSU psychology master's student and co-author, found that participants fell into one of three groups: 79% were consistently married, spending the majority of their lives in one marriage; 8% were consistently single, or, people who spent most of their lives unmarried; and 13% had varied histories, or, a history of moving in and out of relationships, divorce, remarrying or becoming widowed. The researchers then asked participants to rate overall happiness when they were older adults and compared it with the group into which they fell.
"We were surprised to find that lifelong singles and those who had varied relationship histories didn't differ in how happy they were," said Purol. "This suggests that those who have 'loved and lost' are just as happy towards the end of life than those who 'never loved at all.'"
While married people showed a slight uptick in happiness, Purol said the margin was not substantial -- nor what many may expect. If the consistently married group answered a 4 out of 5 on how happy they were, consistently single people answered a 3.82 and those with varied history answered a 3.7.
"When it comes to happiness, whether someone is in a relationship or not is rarely the whole story," Chopik said. "People can certainly be in unhappy relationships, and single people derive enjoyment from all sorts of other parts of their lives, like their friendships, hobbies and work. In retrospect, if the goal is to find happiness, it seems a little silly that people put so much stock in being partnered."
If someone longs for a lifelong partner to start a family and build a happy life together, Chopik and Purol's research suggests that if that individual isn't completely happy to begin with, getting married won't likely dramatically change it all.
"It seems like it may be less about the marriage and more about the mindset," Purol said. "If you can find happiness and fulfillment as a single person, you'll likely hold onto that happiness -- whether there's a ring on your finger or not."
https://www.sciencedaily.com/releases/2020/07/200723115833.htm
Health and happiness depend on each other
July 22, 2020
Science Daily/Association for Psychological Science
Good health and a happy outlook on life may seem like equally worthy yet independent goals. A growing body of research, however, bolsters the case that a happy outlook can have a very real impact on your physical well-being.
New research published in the journal Psychological Scienceshows that both online and in-person psychological interventions -- tactics specifically designed to boost subjective well-being -- have positive effects on self-reported physical health. The online and in-person interventions were equally effective.
"Though prior studies have shown that happier people tend to have better cardiovascular health and immune-system responses than their less happy counterparts," said Kostadin Kushlev, a professor in Georgetown University's Department of Psychology and one of the authors of the paper, "our research is one of the first randomized controlled trials to suggest that increasing the psychological well-being even of generally healthy adults can have benefits to their physical health."
Intervention for Healthy Outcomes
Over the course of six months, Kushlev and his colleagues at the University of Virginia and the University of British Columbia examined how improving the subjective well-being of people who were not hospitalized or otherwise undergoing medical treatment affected their physical health.
A group of 155 adults between the ages of 25 and 75 were randomly assigned either to a wait-list control condition or a 12-week positive psychological intervention that addressed three different sources of happiness: the "Core Self," the "Experiential Self," and the "Social Self."
The first 3 weeks of the program focused on the Core Self, helping individuals identify their personal values, strengths, and goals. The next 5 weeks focused on the Experiential Self, covering emotion regulation and mindfulness. This phase also gave participants tools to identify maladaptive patterns of thinking. The final 4 weeks of the program addressed the Social Self, teaching techniques to cultivate gratitude, foster positive social interactions, and engage more with their community.
The program, called Enduring Happiness and Continued Self-Enhancement (ENHANCE), consisted of weekly modules either led by a trained clinician or completed individually using a customized online platform. None of the modules focused on promoting physical health or health behaviors, such as sleep, exercise, or diet.
Each module featured an hour-long lesson with information and exercises; a weekly writing assignment, such as journaling; and an active behavioral component, such as guided meditation.
"All of the activities were evidence-based tools to increase subjective well-being," Kushlev noted.
When the program concluded, the participants were given individual evaluations and recommendations of which modules would be most effective at improving their happiness in the long term. Three months after the conclusion of the trial, researchers followed up with the participants to evaluate their well-being and health.
A Happy Future
Participants who received the intervention reported increasing levels of subjective well-being over the course of the 12-week program. They also reported fewer sick days than control participants throughout the program and 3 months after it ended.
The online mode of administering the program was shown to be as effective as the in-person mode led by trained facilitators.
"These results speak to the potential of such interventions to be scaled in ways that reach more people in environments such as college campuses to help increase happiness and promote better mental health among students," Kushlev said.
https://www.sciencedaily.com/releases/2020/07/200722170142.htm
Pickled capers activate proteins important for human brain and heart health
New study reveals how a compound found in capers regulates proteins that control important bodily processes
July 13, 2020
Science Daily/University of California - Irvine
A compound commonly found in pickled capers has been shown to activate proteins required for normal human brain and heart activity, and may even lead to future therapies for the treatment of epilepsy and abnormal heart rhythms.
Researchers from the University of California, Irvine School of Medicine have discovered that a compound named quercetin, commonly consumed when eating capers, can directly regulate proteins required for bodily processes such as the heartbeat, thought, muscular contraction, and normal functioning of the thyroid, pancreas and gastrointestinal tract.
Published in Communications Biology, the discovery was made by the laboratory of Geoffrey Abbott, PhD, a professor in the Department of Physiology and Biophysics at the University of California, Irvine School of Medicine. Kaitlyn Redford, a graduate student in the Abbott Lab, was first author of the study titled, "The ubiquitous flavonoid quercetin is an atypical KCNQ potassium channel activator."
The Abbott Lab found that quercetin, a plant-derived bioflavonoid, modulates potassium ion channels in the KCNQ gene family. These channels are highly influential in human health and their dysfunction is linked to several common human diseases, including diabetes, cardiac arrhythmia, and epilepsy.
The study revealed that quercetin modulates the KCNQ channels by directly regulating how they sense electrical activity in the cell, suggesting a previously unexpected mechanism for the therapeutic properties of capers. The mechanism may extend to other quercetin-rich foods in our diet, and quercetin-based nutritional supplements.
"Now that we understand how quercetin controls KCNQ channels," said Abbott, "future medicinal chemistry studies can be pursued to create and optimize quercetin-related small molecules for potential use as therapeutic drugs."
The Abbott Lab screened plant extracts for the ability to alter activity of KCNQ channels and found that one percent extract of pickled capers activated channels important for normal human brain and heart activity. Further studies revealed the molecular mechanism -- quercetin from the caper extract binds to a region of the KCNQ channel required for responding to electrical activity, and in doing so, tricks the channel into opening when it would normally be closed.
"Increasing the activity of KCNQ channels in different parts of the body is potentially highly beneficial," said Abbott. "Synthetic drugs that do this have been used to treat epilepsy and show promise in preventing abnormal heart rhythms."
Archaeological evidence for human caper consumption dates back as far as 10,000 years, according to archaeological findings from Mesolithic soil deposits in Syria and late Stone Age cave dwellings in the Greece and Israel. Capers have traditional been used as folk medicine for hundreds if not thousands of years and are in current use or study for their potential as anti-cancer, anti-diabetic and anti-inflammatory properties, and their possible circulatory and gastrointestinal benefits.
https://www.sciencedaily.com/releases/2020/07/200713144415.htm
People with high cholesterol should eliminate carbs, not saturated fat
July 6, 2020
Science Daily/University of South Florida (USF Innovation)
For decades, people diagnosed with familial hypercholesterolemia have been instructed to minimize their consumption of saturated fats to lower cholesterol and reduce their risks of heart disease. But a new study published in the journal BMJ Evidence-Based Medicine found no evidence to support those claims.
Familial hypercholesterolemia is a genetic disorder that causes people to have cholesterol levels 2-4 times higher than the average person. Organizations, including the American Heart Association, have suggested they avoid eating food from animal sources, such as meat, eggs and cheese, and to avoid coconut oil. An international team of experts on heart disease and diet, including five cardiologists, reviewed dietary guidelines for people with familial hypercholesterolemia. They say they couldn't find any justification for health experts to recommend a low saturated fat diet.
"For the past 80 years, people with familial hypercholesterolemia have been told to lower their cholesterol with a low saturated fat diet," said lead author David Diamond, professor and heart disease researcher at the University of South Florida. "Our study showed that a more 'heart healthy' diet is one low in sugar, not saturated fat."
Diamond and his co-authors say following a low-carb diet is most effective for people at increased risk of heart disease, such as those who are overweight, hypertensive and diabetic. Their findings are consistent with another paper recently published in the "Journal of the American College of Cardiology," which provided strong evidence that food that raises blood sugar, such as bread, potatoes and sweets, should be minimized, rather than tropical oils and animal-based food.
https://www.sciencedaily.com/releases/2020/07/200706113955.htm
Pioneering research reveals certain human genes relate to gut bacteria
June 22, 2020
Science Daily/University of Bristol
The role genetics and gut bacteria play in human health has long been a fruitful source of scientific inquiry, but new research marks a significant step forward in unraveling this complex relationship. Its findings could transform our understanding and treatment of all manner of common diseases, including obesity, irritable bowel syndrome, and Alzheimer's disease.
The international study, led by the University of Bristol and published today in Nature Microbiology, found specific changes in DNA -- the chains of molecules comprising our genetic make-up -- affected both the existence and amount of particular bacteria in the gut.
Lead author Dr David Hughes, Senior Research Associate in Applied Genetic Epidemiology, said: "Our findings represent a significant breakthrough in understanding how genetic variation affects gut bacteria. Moreover, it marks major progress in our ability to know whether changes in our gut bacteria actually cause, or are a consequence of, human disease."
The human body comprises various unique ecosystems, each of which is populated by a vast and diverse array of microorganisms. They include millions of bacteria in the gut, known as the microbiome, that help digest food and produce molecules essential for life, which we cannot produce ourselves. This has prompted researchers to question if gut bacteria may also directly influence human health and disease.
Previous research has identified numerous genetic changes apparently related to bacterial composition in the gut, but only one such association has been observed consistently. This example involves a well-known single mutation that changes whether someone can digest the sugar (lactose) in fresh milk. The same genetic variation also predicts the prevalence of bacteria, Bifidobacterium, that uses or digests lactose as an energy source.
This study, the biggest of its kind, identified 13 DNA changes related to changes in the presence or quantity of gut bacteria. Researchers at Bristol worked with Katholieke Universiteit Leuven and Christian-Albrecht University of Kiel to analyse data from 3,890 individuals from three different population studies: one in Belgium (the Flemish Gut Flora Project) and two in Germany (Food Chain Plus and PopGen). In each individual, the researchers measured millions of known DNA changes and, by sampling their feces, also registered the presence and abundance of hundreds of gut bacteria.
Dr Hughes said: "It was exciting to identify new and robust signals across the three study populations, which makes the correlation of genetic variation and gut bacteria much more striking and compelling. Now comes the great challenge of confirming our observations with other studies and dissecting how exactly these DNA changes might impact bacterial composition."
Such investigations could hold the key to unlocking the intricate biological mechanisms behind some of the biggest health challenges of our time.
Study co-author Dr Kaitlin Wade, Lecturer in Epidemiology at the University of Bristol, said: "A strength here is that these findings provide a groundwork for causal analyses to determine, for instance, whether the presence of specific bacteria increases the risk of a disease or is a manifestation of it."
"The implications for our understanding of human health and our approach to medicine are far-reaching and potentially game changing."
https://www.sciencedaily.com/releases/2020/06/200622133018.htm
Even 'low-risk' drinking can be harmful
June 15, 2020
Science Daily/Journal of Studies on Alcohol and Drugs
It's not just heavy drinking that's a problem -- even consuming alcohol within weekly low-risk drinking guidelines can result in hospitalization and death, according to a new study published in the Journal of Studies on Alcohol and Drugs.
Moderate drinkers "are not insulated from harm," write researchers led by Adam Sherk, Ph.D., of the Canadian Institute for Substance Use Research at the University of Victoria in British Columbia, Canada.
The Canadian government's low-risk drinking guidelines state that women should consume no more than about 10 drinks per week and men no more than 15. (A "drink" is 12 oz. of beer, 5 oz. of wine, or 1.5 oz. of liquor.) These limits are slightly higher than those in the United States and exceed those of most other high-income countries.
In their research, Sherk and colleagues found that, in British Columbia, a significant portion of alcohol-caused death and disability was experienced by those drinking within these guidelines. For example, more than 50 percent of cancer deaths resulting from alcohol use occurred in people drinking moderately. Further, 38 percent of all alcohol-attributable deaths were experienced by people drinking below the weekly limits or among former drinkers.
However, for women, alcohol consumption within the guidelines did offer some protection from death from heart attack, stroke and diabetes. Nonetheless, "[t]his protective effect did not appear to hold for men," the authors write, "who experienced harm at all drinking levels."
For their study, the investigators used a new, open-access model -- the International Model of Alcohol Harms and Policies (InterMAHP) -- which can be used to estimate alcohol harms in a country or state, in total or by drinking group. They used British Columbia-specific alcohol exposure data from substance use surveys, hospital data from the Canadian Institute for Health Information and mortality data from Statistics Canada's Vital Statistics. These sources were nonidentifying and for 2014.
Because of these results, Sherk and colleagues say that some national drinking guidelines, which are published by many countries to help drinkers make informed health decisions, may be too high. This may be particularly true in Canada, where the research was conducted.
Sherk suggests that guideline limits should be lowered to match those in the Netherlands: "Don't drink or, if you do, drink no more than one drink per day."
Overall, he says, the best advice for drinking is to err on the side of caution, "When it comes to alcohol use, less is better."
https://www.sciencedaily.com/releases/2020/06/200615092744.htm
Adult stem cell study shows fish oil may help with depression
Researchers use stem cells from adults with depression to test treatments
June 11, 2020
Science Daily/University of Illinois at Chicago
A study published in Molecular Psychiatry shows that patient-derived adult stem cells can be used to model major depressive disorder and test how a patient may respond to medication.
Using stem cells from adults with a clinical diagnosis of depression, the University of Illinois at Chicago researchers who conducted the study also found that fish oil, when tested in the model, created an antidepressant response.
UIC's Mark Rasenick, principal investigator of the study, says that the research provides a number of novel findings that can help scientists better understand how the brain works and why some people respond to drug treatment for depression, while others experience limited benefits from antidepressant medication.
"It was also exciting to find scientific evidence that fish oil -- an easy-to-get, natural product -- may be an effective treatment for depression," said Rasenick, UIC distinguished professor of physiology and biophysics and psychiatry at the College of Medicine.
Major depressive disorder, or depression, is the most common psychiatric disorder. Around one in six individuals will experience at least one depressive episode in their lifetime. However, antidepressant treatment fails in about one-third of patients.
In the study, the UIC researchers used skin cells from adults with depression that were converted into stem cells at Massachusetts General Hospital and then directed those stem cells to develop into nerve cells. The skin biopsies were taken from two types of patients: people who previously responded to antidepressant treatment and people who have previously been resistant to antidepressants.
When fish oil was tested, the models from treatment-sensitive and treatment-resistant patients both responded.
Rasenick says the response was similar to that seen from prescription antidepressants, but it was produced through a different mechanism.
"We saw that fish oil was acting, in part, on glial cells, not neurons," said Rasenick, who is also a research career scientist at Jesse Brown VA Medical Center and president and chief scientific officer at Pax Neuroscience, a UIC startup company. "For many years, scientists have paid scant attention to glia -- a type of brain cell that surrounds neurons -- but there is increasing evidence that glia may play a role in depression. Our study suggests that glia may also be important for antidepressant action.
"Our study also showed that a stem cell model can be used to study response to treatment and that fish oil as a treatment, or companion to treatment, for depression warrants further investigation," Rasenick said.
https://www.sciencedaily.com/releases/2020/06/200611143054.htm
Volunteerism: Doing good does you good
June 11, 2020
Science Daily/Elsevier
A new study in the American Journal of Preventive Medicine, published by Elsevier, takes a closer look at the benefits of volunteering to the health and well-being of volunteers, both validating and refuting findings from previous research. The results verify that adults over 50 who volunteer for at least 100 hours a year (about two hours per week) have a substantially reduced risk of mortality and developing physical limitations, higher levels of subsequent physical activity, and improved sense of well-being later on compared to individuals who do not volunteer.
"Humans are social creatures by nature. Perhaps this is why our minds and bodies are rewarded when we give to others. Our results show that volunteerism among older adults doesn't just strengthen communities, but enriches our own lives by strengthening our bonds to others, helping us feel a sense of purpose and well-being, and protecting us from feelings of loneliness, depression, and hopelessness. Regular altruistic activity reduces our risk of death even though our study didn't show any direct impact on a wide array of chronic conditions," explained lead investigator Eric S. Kim, PhD, Department of Social and Behavioral Sciences and Lee Kum Sheung Center for Health and Happiness, Harvard T.H. Chan School of Public Health, Boston; and Human Flourishing Program, Institute for Quantitative Social Science, Harvard University, Cambridge, MA, USA.
A growing body of research has linked volunteering to many health and well-being benefits, but there is still insufficient evidence to demonstrate the consistent and specific positive outcomes that are needed to develop public health interventions based on volunteerism. This large-scale study helps address this gap by evaluating 34 physical health and psychological/social well-being outcomes. This permitted direct comparisons of the potential size of effect that volunteering might have on various outcomes and also learn which outcomes volunteering does not appear to be influencing.
The study did not confirm links between volunteering and improvements to chronic conditions such as diabetes, hypertension, stroke, cancer, heart disease, lung disease, arthritis, obesity, cognitive impairment, or chronic pain.
The analysis was based on data, face-to-face interviews, and survey responses from nearly 13,000 participants randomly selected from the Health and Retirement Study (HRS), a nationally representative sample of older adults in the United States. The participants were tracked over four years in two cohorts from 2010-2016.
The growing older adult population possesses a vast array of skills and experiences that can be leveraged for the greater good of society via volunteering. While proposing further research to better understand this phenonmena, the study recommends the adoption of policies that encourage more volunteerism. Such interventions could simultaneously enhance society and foster a trajectory of healthy aging in the rapidly growing population of older adults. Further study is also needed to learn the underlying reasons for the divergence in some of the results from previous research.
A cautionary note is that these conclusions were drawn prior to the global COVID-19 pandemic, which makes social activity risky and unadvisable for the foreseeable future. However, Dr. Kim noted that "now might be a particular moment in history when society needs your service the most. If you are able to do so while abiding by health guidelines, you not only can help to heal and repair the world, but you can help yourself as well. When the COVID-19 crisis finally subsides, we have a chance to create policies and civic structures that enable more giving in society. Some cities were already pioneering this idea before the pandemic and quarantine, and I hope we have the willingness and resolve to do so in a post-COVID-19 society as well."
https://www.sciencedaily.com/releases/2020/06/200611094136.htm
The dreaming brain tunes out the outside world
May 15, 2020
Science Daily/CNRS
Scientists from the CNRS and the ENS-PSL in France and Monash University in Australia have shown that the brain suppresses information from the outside world, such as the sound of a conversation, during the sleep phase linked to dreaming. This ability could be one of the protective mechanisms of dreams. The study, carried out in collaboration with the Centre du Sommeil et de la Vigilance, Hôtel-Dieu, AP-HP -- Université de Paris, is published in Current Biology on 14 May 2020.
While we dream, we invent worlds that bear no relation to the quietness of our bedroom. In fact, it is rather unusual for elements of our immediate environment to be incorporated into our dreams. To better understand how the brain protects itself from outside influences, researchers invited 18 participants to a morning nap in the lab. Morning sleep is rich in dreams. Dreams mostly occur during what is known as REM sleep, since the brain is somehow in a waking state during this phase of sleep, showing brain activity similar to that when a person is awake. The body, on the other hand, is paralysed, although not entirely. During certain phases of REM sleep, the eyes continue to move. Research has shown that such movements are related to dreaming.
To study how the dreaming brain interacts with external sounds, the scientists got volunteer sleepers to listen to stories in French mixed with meaningless language. By combining the electroencephalogram with a machine learning technique, they confirmed that, even when the brain is asleep, it continues to record everything that goes on around it. They also showed that, during light sleep, the brain prioritises meaningful speech, just as it does when in the waking state. However, such speech is actively filtered out during eye movement phases in REM sleep. In other words, our sleeping brain can select information from the outside world and flexibly amplify or suppress it, depending on whether or not it is immersed in a dream!
The team believe that this mechanism enables the brain to protect the dreaming phase, which is necessary for emotional balance and consolidation of the day's learning. Although dreams are predominant during periods of eye movement, they can also occur during other phases of sleep. Are they then accompanied by a similar suppression of sensations from the outside world?
https://www.sciencedaily.com/releases/2020/05/200515131915.htm