Study: Friends ‘Better than Morphine’

Study: Friends ‘Better than Morphine’

People with more friends have higher pain tolerance, Oxford University researchers have found.

Katerina Johnson, a doctoral student in the University’s Departments of Psychiatry and Experimental Psychology, was studying whether differences in our neurobiology may help explain why some of us have larger social networks than others.

She said: ‘I was particularly interested in a chemical in the brain called endorphin.  Endorphins are part of our pain and pleasure circuitry – they’re our body’s natural painkillers and also give us feelings of pleasure.  Previous studies have suggested that endorphins promote social bonding in both humans and other animals. One theory, known as the brain opioid theory of social attachment, is that social interactions trigger positive emotions when endorphin binds to opioid receptors in the brain.  This gives us that feel-good factor that we get from seeing our friends.

These results are also interesting because recent research suggests that the endorphin system may be disrupted in psychological disorders such as depression.

Katerina Johnson, Department of Experimental Psychology

‘To test this theory, we relied on the fact that endorphin has a powerful pain-killing effect – stronger even than morphine.’

The researchers therefore used pain tolerance as a way to assess the brain’s endorphin activity.  If the theory was correct, people with larger social networks would have higher pain tolerance, and this was what their study found.  Friendships may really help take the pain away!

Katerina commented:  ‘These results are also interesting because recent research suggests that the endorphin system may be disrupted in psychological disorders such as depression.  This may be part of the reason why depressed people often suffer from a lack of pleasure and become socially withdrawn.’

There were also two other findings of note.  Both fitter people and those with higher reported stress levels tended to have smaller social networks.

Katerina explained: ‘It may simply be a question of time – individuals that spend more time exercising have less time to see their friends.  However, there may be a more interesting explanation – since both physical and social activities promote endorphin release, perhaps some people use exercise as an alternative means to get their ‘endorphin rush’ rather than socialising.  The finding relating to stress may indicate that larger social networks help people to manage stress better, or it may be that stress or its causes mean people have less time for social activity, shrinking their network.

‘Studies suggest that the quantity and quality of our social relationships affect our physical and mental health and may even be a factor determining how long we live.  Therefore, understanding why individuals have different social networks sizes and the possible neurobiological mechanisms involved is an important research topic.  As a species, we’ve evolved to thrive in a rich social environment but in this digital era, deficiencies in our social interactions may be one of the overlooked factors contributing to the declining health of our modern society.’

How the research was carried out

Participants were asked to complete a questionnaire relating to the two innermost social network layers (approximately corresponding to those individuals contacted at least once a week and once a month respectively), as well as providing information on lifestyle and personality.  They then performed a test which involved squatting against the wall with knees at a 90° angle and a straight back (the wall sit test).  They were asked to hold this position and endure the discomfort for as long as possible.  Even when allowing for differences in individual fitness, the study found that people who could endure this pain test for longer, also tended to have larger social networks.

The paper, Pain Tolerance predicts human social network size, is published in Scientific Reports (DOI:10.1038/srep25267).

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Radiant Zinc Fireworks Reveal Quality of Human Egg

Radiant Zinc Fireworks Reveal Quality of Human Egg

CHICAGO — A stunning explosion of zinc fireworks occurs when a human egg is activated by a sperm enzyme, and the size of these “sparks” is a direct measure of the quality of the egg and its ability to develop into an embryo, according to new research from Northwestern Medicine.

The discovery has potential to help doctors choose the best eggs to transfer during in vitro fertilization (IVF), the scientists said.

This is the first time the zinc sparks have been documented in a human egg.

“This means if you can look at the zinc spark at the time of fertilization, you will know immediately which eggs are the good ones to transfer in in vitro fertilization (IVF),” said Teresa Woodruff, one of the study’s two senior authors and an expert in ovarian biology at Northwestern. “It’s a way of sorting egg quality in a way we’ve never been able to assess before.”

Woodruff is the Thomas J. Watkins Memorial Professor in Obstetrics and Gynecology at Northwestern University Feinberg School of Medicine and director of Northwestern’s Center for Reproductive Science.

Scientists activated the egg by injecting a sperm enzyme into the egg that triggers calcium to increase within the egg and zinc to be released from the egg. (The eggs in the study were not fertilized with actual sperm because that is not permitted in human research under federal law.)

“It was remarkable,” Woodruff said. “We discovered the zinc spark just five years ago in the mouse, and to see the zinc radiate out in a burst from each human egg was breathtaking.

“All of biology starts at the time of fertilization, yet we know next to nothing about the events that occur in the human. This discovery required a unique partnership between biologists and chemists and non-federal dollars to support the research,” she said.

The study was published April 26 in Scientific Reports.

As the zinc is released from the egg, it binds to small molecule probes, which emit light in fluorescence microscopy experiments. Thus the rapid zinc release can be followed as a flash of light that appears as a spark.

“These fluorescence microscopy studies establish that the zinc spark occurs in human egg biology, and that can be observed outside of the cell,” said Tom O’Halloran, a co-senior author.  O’Halloran is the Charles E. and Emma H. Morrison Professor in Chemistry in the Weinberg College of Arts and Sciences and director of Northwestern’s Chemistry of Life Processes Institute.

Eggs compartmentalize and distribute zinc to control the development of a healthy embryo. Over the last six years this team has shown that zinc controls the decision to grow and change into a completely new genetic organism.

“This is an important discovery because it may give us a non-invasive and easily visible way to assess the health of an egg and eventually an embryo before implantation,” said co-author Dr. Eve Feinberg, who took care of the patients who provided eggs for the basic science study and collaborated with the research team.

Feinberg will become an assistant professor of obstetrics and gynecology at Feinberg and will be ambulatory medical director of Northwestern Medicine’s Fertility and Reproductive Medicine division beginning July 1. Feinberg currently is a physician at Fertility Centers of Illinois (FCI).

“There are no tools currently available that tell us if it’s a good quality egg,” Feinberg said. “Often we don’t know whether the egg or embryo is truly viable until we see if a pregnancy ensues. That’s the reason this is so transformative. If we have the ability up front to see what is a good egg and what’s not, it will help us know which embryo to transfer, avoid a lot of heartache and achieve pregnancy much more quickly.”

First author Francesca Duncan made the human zinc spark discovery. “We now know that the release of zinc at the time of fertilization is a conserved phenomenon, which will help us address one of the largest unanswered questions in reproductive medicine — what makes a good egg?” Duncan said.

Duncan was an assistant research professor in obstetrics and gynecology at Feinberg when she made the discovery and will become the executive director of Northwestern’s Center for Reproductive Science on August 1. She is currently an assistant professor at the University of Kansas Medical Center. Emily Que and Nan Zhang are co-first authors.

In a companion paper published in Scientific Reports on March 18, a zinc spark is shown at the precise time a sperm enters a mouse egg. This discovery was made by Zhang, a postdoctoral fellow at Northwestern. Zhang said little is known about the events that occur at the time of fertilization, because it is difficult to capture the precise time of sperm entry.

The paper is titled “The Zinc Spark is an Inorganic Signature of Human Egg Activation.”

The research was supported by the Thomas J. Watkins Endowment and a research grant from Ferring Pharmaceuticals and the W.M. Keck Foundation. All human egg activation studies were done exclusively with samples from FCI and funds from Ferring Pharmaceuticals.

Tamping Down Neurons’ Energy Use Could Treat Neurodegeneration

Tamping Down Neurons’ Energy Use Could Treat Neurodegeneration

Salk Institute scientists showed how an FDA-approved drug boosts the health of brain cells by limiting their energy use. Like removing unnecessary lighting from a financially strapped household to save on electricity bills, the drug–called rapamycin–prolongs the survival of diseased neurons by forcing them to reduce protein production to conserve cellular energy.

Rapamycin has been shown to extend lifespan and reduce symptoms in a broad range of diseases and, at the cellular level, is known to slow down the rate at which proteins are made. But the new Salk research, published in the journal eLife, suggests that rapamycin could also target the neural damage associated with Leigh syndrome, a rare genetic disease, and potentially other forms of neurodegeneration as well.

Salk scientists show how the drug rapamycin (bottom) rescues Leigh syndrome neurons. Credit: Salk Institute.

“Our study shows that protein production in neurons is one of the major utilizers of energy and that neurons of Leigh syndrome degenerate because they can’t sustain a high enough level of energy,” says Tony Hunter, the Renato Dulbecco Chair and American Cancer Society Professor in Salk’s Molecular and Cell Biology Laboratory, who led the research.

Previous studies on rapamycin, which blocks a key energy sensor in cells, found that it can alter the immune system, extend lifespan and treat disorders, including lupus and Alzheimer’s disease. Researchers assumed that the drug prevented the neurodegeneration seen in Alzheimer’s by encouraging cells to degrade damaged components and aggregated proteins. But recent data hinted that the drug might also have an effect on the mitochondria, organelles that act as cells’ powerhouses, producing energy in the form of adenosine triphosphate (ATP).

Xinde Zheng, a research associate in the Hunter lab, was already studying the properties of cells affected by Leigh syndrome, whose inherited neurodegeneration is caused by a mutation in mitochondrial DNA that reduces ATP production. Zheng wondered how rapamycin would affect the neurons plagued by the diseased mitochondria. He and Hunter teamed up with the lab of Rusty Gage, a professor in Salk’s Laboratory of Genetics and holder of the Vi and John Adler Chair for Research on Age-Related Neurodegenerative Disease. Zheng, together with Leah Boyer, then a researcher in Gage’s lab and now director of Salk’s Stem Cell Core, generated diseased neurons by taking skin cells from patients with Leigh syndrome, reprogramming them into stem cells in culture and then coaxing them to develop into brain cells in a dish.

Though cells must make proteins to survive, protein production is a highly energy-consuming process and, for diseased cells, the process leaves too few energy reserves to deal with cellular stress or other demands.

“Reducing protein production in aging neurons allows more energy for the cell to put toward folding proteins correctly and handling stress,” says Zheng, the first author of the new paper. “The impact of our finding is that modulation of protein synthesis could be a general approach to treating neurodegeneration.”

In their study, the team found that Leigh Syndrome neurons decayed in the dish and showed clear signs of energy depletion. Meanwhile, Leigh syndrome neurons exposed to rapamycin had more ATP and showed less degeneration. By turning down the dial on protein production, the diseased and damaged neurons were able to survive longer.

“We are surprised and delighted that rapamycin’s effect to reduce protein synthesis as an energy-austerity approach may lead to a potential treatment for mitochondria-related neurodegenerative diseases,” says Gage.

This is a good example of the value of studying a disease in a dish, according to Hunter. “It’s led to a lot of new insights into the underlying biology of this rare and understudied condition,” he adds.

More work is needed to determine whether the findings on rapamycin hold true in animal models of Leigh syndrome and other neurodegenerative diseases, and to ascertain how exactly rapamycin is altering the metabolism of the cells.

Despite Their Small Brains—Ravens Are Just As Clever As Chimps

Despite Their Small Brains—Ravens Are Just As Clever As Chimps

A study led by researchers at Lund University in Sweden suggests that ravens can be as clever as chimpanzees, despite having much smaller brains, indicating that rather than the size of the brain, the neuronal density and the structure of the birds’ brains play an important role in terms of their intelligence.

“Absolute brain size is not the whole story. We found that corvid birds performed as well as great apes, despite having much smaller brains,” says Can Kabadayi, doctoral student in Cognitive Science.

Intelligence is difficult to test, but one aspect of being clever is inhibitory control, and the ability to override animal impulses and choose a more rational behaviour. Researchers at Duke University, USA, conducted a large-scale study in 2014, where they compared the inhibitory control of 36 different animal species, mainly primates and apes. The team used the established cylinder test, where food is placed in a transparent tube with openings on both sides. The challenge for the animal is to retrieve the food using the side openings, instead of trying to reach for it directly. To succeed, the animal has to show constraint and choose a more efficient strategy for obtaining the food.

The large-scale study concluded that great apes performed the best, and that absolute brain size appeared to be key when it comes to intelligence. However, they didn’t conduct the cylinder test on corvid birds.

Can Kabadayi, together with researchers from the University of Oxford, UK and the Max Planck Institute for Ornithology in Germany, therefore had ravens, jackdaws and New Caledonian crows perform the same cylinder test to better understand their inhibitory control.

The team first trained the birds to obtain a treat in an opaque tube with a hole at each end. Then they repeated the test with a transparent tube. The animal impulse would naturally be to go straight for the tube as they saw the food. However, all of the ravens chose to enter the tube from the ends in every try. The performance of the jackdaws and the crows came very close to 100%, comparable to a performance by bonobos and gorillas.

“This shows that bird brains are quite efficient, despite having a smaller absolute brain size. As indicated by the study, there might be other factors apart from absolute brain size that are important for intelligence, such as neuronal density,” says Can Kabadayi, and continues:

“There is still so much we need to understand and learn about the relationship between intelligence and brain size, as well as the structure of a bird’s brain, but this study clearly shows that bird brains are not simply birdbrains after all!”

Hubble Discovers Moon Orbiting the Dwarf Planet Makemake

Hubble Discovers Moon Orbiting the Dwarf Planet Makemake

Peering to the outskirts of our solar system, NASA’s Hubble Space Telescope has spotted a small, dark moon orbiting Makemake, the second brightest icy dwarf planet — after Pluto — in the Kuiper Belt.

The moon — provisionally designated S/2015 (136472) 1 and nicknamed MK 2 — is more than 1,300 times fainter than Makemake. MK 2 was seen approximately 13,000 miles from the dwarf planet, and its diameter is estimated to be 100 miles across. Makemake is 870 miles wide. The dwarf planet, discovered in 2005, is named for a creation deity of the Rapa Nui people of Easter Island.

The Kuiper Belt is a vast reservoir of leftover frozen material from the construction of our solar system 4.5 billion years ago and home to several dwarf planets. Some of these worlds have known satellites, but this is the first discovery of a companion object to Makemake. Makemake is one of five dwarf planets recognized by the International Astronomical Union.

The observations were made in April 2015 with Hubble’s Wide Field Camera 3. Hubble’s unique ability to see faint objects near bright ones, together with its sharp resolution, allowed astronomers to pluck out the moon from Makemake’s glare. The discovery was announced today in a Minor Planet Electronic Circular.

This Hubble image reveals the first moon ever discovered around the dwarf planet Makemake. The tiny satellite, located just above Makemake in this image, is barely visible because it is almost lost in the glare of the very bright dwarf planet. Hubble’s sharp-eyed WFC3 made the observation in April 2015. Credits: NASA, ESA, and A. Parker and M. Buie (SwRI)
This Hubble image reveals the first moon ever discovered around the dwarf planet Makemake. The tiny satellite, located just above Makemake in this image, is barely visible because it is almost lost in the glare of the very bright dwarf planet. Hubble’s sharp-eyed WFC3 made the observation in April 2015. Credits: NASA, ESA, and A. Parker and M. Buie (SwRI)

The observing team used the same Hubble technique to observe the moon as they did for finding the small satellites of Pluto in 2005, 2011, and 2012. Several previous searches around Makemake had turned up empty. “Our preliminary estimates show that the moon’s orbit seems to be edge-on, and that means that often when you look at the system you are going to miss the moon because it gets lost in the bright glare of Makemake,” said Alex Parker of Southwest Research Institute, Boulder, Colorado, who led the image analysis for the observations.

A moon’s discovery can provide valuable information on the dwarf-planet system. By measuring the moon’s orbit, astronomers can calculate a mass for the system and gain insight into its evolution.

Uncovering the moon also reinforces the idea that most dwarf planets have satellites.

“Makemake is in the class of rare Pluto-like objects, so finding a companion is important,” Parker said. “The discovery of this moon has given us an opportunity to study Makemake in far greater detail than we ever would have been able to without the companion.”

Finding this moon only increases the parallels between Pluto and Makemake. Both objects are already known to be covered in frozen methane. As was done with Pluto, further study of the satellite will easily reveal the density of Makemake, a key result that will indicate if the bulk compositions of Pluto and Makemake are also similar. “This new discovery opens a new chapter in comparative planetology in the outer solar system,” said team leader Marc Buie of the Southwest Research Institute, Boulder, Colorado.

The researchers will need more Hubble observations to make accurate measurements to determine if the moon’s orbit is elliptical or circular. Preliminary estimates indicate that if the moon is in a circular orbit, it completes a circuit around Makemake in 12 days or longer.

Determining the shape of the moon’s orbit will help settle the question of its origin. A tight circular orbit means that MK 2 is probably the product of a collision between Makemake and another Kuiper Belt Object. If the moon is in a wide, elongated orbit, it is more likely to be a captured object from the Kuiper Belt. Either event would have likely occurred several billion years ago, when the solar system was young.

The discovery may have solved one mystery about Makemake. Previous infrared studies of the dwarf planet revealed that while Makemake’s surface is almost entirely bright and very cold, some areas appear warmer than other areas. Astronomers had suggested that this discrepancy may be due to the sun warming discrete dark patches on Makemake’s surface. However, unless Makemake is in a special orientation, these dark patches should make the dwarf planet’s brightness vary substantially as it rotates. But this amount of variability has never been observed.

These previous infrared data did not have sufficient resolution to separate Makemake from MK 2. The team’s reanalysis, based on the new Hubble observations, suggests that much of the warmer surface detected previously in infrared light may, in reality, simply have been the dark surface of the companion MK 2.

First moon discovered around dwarf planet Makemake
This artist’s concept shows the distant dwarf planet Makemake and its newly discovered moon. Makemake and its moon, nicknamed MK 2, are more than 50 times farther away than Earth is from the sun. Credits: NASA, ESA, and A. Parker (Southwest Research Institute)

There are several possibilities that could explain why the moon would have a charcoal-black surface, even though it is orbiting a dwarf planet that is as bright as fresh snow. One idea is that, unlike larger objects such as Makemake, MK 2 is small enough that it cannot gravitationally hold onto a bright, icy crust, which sublimates, changing from solid to gas, under sunlight. This would make the moon similar to comets and other Kuiper Belt Objects, many of which are covered with very dark material.

When Pluto’s moon Charon was discovered in 1978, astronomers quickly calculated the mass of the system. Pluto’s mass was hundreds of times smaller than the mass originally estimated when it was found in 1930. With Charon’s discovery, astronomers suddenly knew something was fundamentally different about Pluto. “That’s the kind of transformative measurement that having a satellite can enable,” Parker said.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

Risks of Harm from Spanking Confirmed by Analysis of Five Decades of Research

Risks of Harm from Spanking Confirmed by Analysis of Five Decades of Research

The more children are spanked, the more likely they are to defy their parents and to experience increased anti-social behavior, aggression, mental health problems and cognitive difficulties, according to a new meta-analysis of 50 years of research on spanking by experts at the University of Texas at Austin and the University of Michigan.

The study, published in this month’s Journal of Family Psychology, looks at five decades of research involving over 160,000 children. The researchers say it is the most complete analysis to date of the outcomes associated with spanking, and more specific to the effects of spanking alone than previous papers, which included other types of physical punishment in their analyses.

“Our analysis focuses on what most Americans would recognize as spanking and not on potentially abusive behaviors,” says Elizabeth Gershoff, an associate professor of human development and family sciences at The University of Texas at Austin. “We found that spanking was associated with unintended detrimental outcomes and was not associated with more immediate or long-term compliance, which are parents’ intended outcomes when they discipline their children.”

Gershoff and co-author Andrew Grogan-Kaylor, an associate professor at the University of Michigan School of Social Work, found that spanking (defined as an open-handed hit on the behind or extremities) was significantly linked with 13 of the 17 outcomes they examined, all in the direction of detrimental outcomes.

“The upshot of the study is that spanking increases the likelihood of a wide variety of undesired outcomes for children. Spanking thus does the opposite of what parents usually want it to do,” Grogan-Kaylor says.

Gershoff and Grogan-Kaylor tested for some long-term effects among adults who were spanked as children. The more they were spanked, the more likely they were to exhibit anti-social behavior and to experience mental health problems. They were also more likely to support physical punishment for their own children, which highlights one of the key ways that attitudes toward physical punishment are passed from generation to generation.

The researchers looked at a wide range of studies and noted that spanking was associated with negative outcomes consistently and across all types of studies, including those using the strongest methodologies such as longitudinal or experimental designs. As many as 80 percent of parents around the world spank their children, according to a 2014 UNICEF report. Gershoff notes that this persistence of spanking is in spite of the fact that there is no clear evidence of positive effects from spanking and ample evidence that it poses a risk of harm to children’s behavior and development.

Both spanking and physical abuse were associated with the same detrimental child outcomes in the same direction and nearly the same strength.

“We as a society think of spanking and physical abuse as distinct behaviors,” she says. “Yet our research shows that spanking is linked with the same negative child outcomes as abuse, just to a slightly lesser degree.”

Gershoff also noted that the study results are consistent with a report released recently by the Centers for Disease Control and Prevention that called for “public engagement and education campaigns and legislative approaches to reduce corporal punishment,” including spanking, as a means of reducing physical child abuse. “We hope that our study can help educate parents about the potential harms of spanking and prompt them to try positive and non-punitive forms of discipline.”

First Happiness Genes Have Been Located

First Happiness Genes Have Been Located

For the first time in history, researchers have isolated the parts of the human genome that could explain the differences in how humans experience happiness. These are the findings of a large-scale international study in over 298,000 people, conducted by VU Amsterdam professors Meike Bartels (Genetics and Wellbeing) and Philipp Koellinger (Genoeconomics). The researchers found three genetic variants for happiness, two variants that can account for differences in symptoms of depression, and eleven locations on the human genome that could account for varying degrees of neuroticism. The genetic variants for happiness are mainly expressed in the central nervous system and the adrenal glands and pancreatic system. The results were published in the journal Nature Genetics.

Genetic influences on happiness

Prior twin and family research using information from the Netherlands Twin Register and other sources has shown that individual differences in happiness and well-being can be partially ascribed to genetic differences between people. Happiness and wellbeing are the topics of an increasing number of scientific studies in a variety of academic disciplines. Policy makers are increasingly focusing on wellbeing, drawing primarily on the growing body of evidence suggesting that wellbeing is a factor in mental and physical health.

VU Amsterdam professor Meike Bartels explains: “This study is both a milestone and a new beginning: A milestone because we are now certain that there is a genetic aspect to happiness and a new beginning because the three variants that we know are involved account for only a small fraction of the differences between human beings. We expect that many variants will play a part.” Locating these variants will also allow us to better study the interplay between nature and nurture, as the environment is certainly responsible — to some extent — for differences in the way people experience happiness.”

Further research is now possible

These findings, which resulted from a collaborative project with the Social Science Genetic Association Consortium, are available for follow-up research. This will create an increasingly clearer picture of what causes differences in happiness. Professor Bartels points out that “The genetic overlap with depressive symptoms that we have found is also a breakthrough. This shows that research into happiness can also offer new insights into the causes of one of the greatest medical challenges of our time: depression.” The research effort headed by professors Bartels and Koellinger is the largest ever study into the genetic variants for happiness. It was successfully completed thanks to the assistance of 181 researchers from 145 scientific institutes, including medical centres in Rotterdam, Groningen, Leiden and Utrecht, and the universities of Rotterdam and Groningen.