‘Trust hormone’ oxytocin helps old muscle work like new, study finds

UC Berkeley researchers have discovered that oxytocin — a hormone associated with maternal nurturing, social attachments, childbirth and sex — is indispensable for healthy muscle maintenance and repair, and that in mice it declines with age.

The new study published today (June 10) in the journal Nature Communications, presents oxytocin as the latest treatment target for age-related muscle wasting, or sarcopenia.

The healthy muscle tissue on the left is from a young mouse. The ability of muscle to repair itself decreases with age, as evidenced by the middle image of old muscle tissue, which shows a lower density of muscle fibers, increased scar tissue and inflammation. The addition of oxytocin to the blood of old mice rapidly rejuvenates the old muscle, as shown on the right. (Photos by Wendy Cousin and Christian Elabd, UC Berkeley)

A few other biochemical factors in blood have been connected to aging and disease in recent years, but oxytocin is the first anti-aging molecule identified that is approved by the Food and Drug Administration for clinical use in humans, the researchers said. Pitocin, a synthetic form of oxytocin, is already used to help with labor and to control bleeding after childbirth. Clinical trials of an oxytocin nasal spray are also underway to alleviate symptoms associated with mental disorders such as autism, schizophrenia and dementia.

“Unfortunately, most of the molecules discovered so far to boost tissue regeneration are also associated with cancer, limiting their potential as treatments for humans,” said study principal investigator Irina Conboy, associate professor of bioengineering. “Our quest is to find a molecule that not only rejuvenates old muscle and other tissue, but that can do so sustainably long-term without increasing the risk of cancer.”

Conboy and her research team say that oxytocin, secreted into the blood by the brain’s pituitary gland, is a good candidate because it is a broad range hormone that reaches every organ, and it is not known to be associated with tumors or to interfere with the immune system.

A happy hormone

Oxytocin is sometimes referred to as the “trust hormone” because of its association with romance and friendship. It is released with a warm hug, a grasped hand or a loving gaze, and it increases libido. The hormone kicks into high gear during and after childbirth, helping new mothers bond with and breastfeed their new babies.

“This is the hormone that makes your heart melt when you see kittens, puppies and human babies,” said Conboy, who is also a member of the Berkeley Stem Cell Center and of the California Institute for Quantitative Biosciences (QB3). “There is an ongoing joke among my research team that we’re all happy, friendly and trusting because oxytocin permeates the lab.”

The researchers pointed out that while oxytocin is found in both young boys and girls, it is not yet known when levels of the hormone start to decline in humans, and what levels are necessary for maintaining healthy tissues.

Christian Elabd and Wendy Cousin, both senior scientists in Conboy’s lab, were co-lead authors on this study.

Previous research by Elabd found that administering oxytocin helped prevent the development of osteoporosis in mice that had their ovaries removed to mimic menopause.

Extra oxytocin more beneficial for the old

The new study determined that in mice, blood levels of oxytocin declined with age. They also showed that there are fewer receptors for oxytocin in muscle stem cells in old versus young mice.

To tease out oxytocin’s role in muscle repair, the researchers injected the hormone under the skin of old mice for four days, and then for five days more after the muscles were injured. After the nine-day treatment, they found that the muscles of the mice that had received oxytocin injections healed far better than those of a control group of mice without oxytocin.

“The action of oxytocin was fast,” said Elabd. “The repair of muscle in the old mice was at about 80 percent of what we saw in the young mice.”

Interestingly, giving young mice an extra boost of oxytocin did not seem to cause a significant change in muscle regeneration.

“This is good because it demonstrates that extra oxytocin boosts aged tissue stem cells without making muscle stem cells divide uncontrollably,” Cousin added.

The researchers also found that blocking the effects of oxytocin in young mice rapidly compromised their ability to repair muscle, which resembled old tissue after an injury.

The researchers also studied mice whose gene for oxytocin was disabled, and compared them with a group of control mice. At a young age, there was no significant difference between the two groups in muscle mass or repair efficiency after an injury. It wasn’t until the mice with the disabled oxytocin gene reached adulthood that signs of premature aging began to appear.

“When disabling other types of genes associated with tissue repair, defects appear right away either during embryonic development, or early in life,” said Conboy. “To our knowledge, the oxytocin gene is the only one whose impact is seen later in life, suggesting that its role is closely linked to the aging process.”

Future treatment options

Cousin noted that oxytocin could become a viable alternative to hormone replacement therapy as a way to combat the symptoms of both female and male aging, and for long-term health. Hormone therapy did not show improvements in agility or muscle regeneration ability, and it is no longer recommended for disease prevention because research has found that the therapy’s benefits did not outweigh its health risks.

In addition to healthy muscle, oxytocin is predicted to improve bone health, and it might be important in combating obesity.

Conboy said her lab plans to examine oxytocin’s role in extending a healthy life in animals, and in conserving its beneficial anti-aging effects in humans.

She noted that there is a growing circle of scientists who believe that aging is the underlying cause of a number of chronic diseases, including Parkinson’s and Type 2 diabetes.

“If you target processes associated with aging, you may be tackling those diseases at the same time,” said Conboy. “Aging is a natural process, but I believe that we can meaningfully intervene with age-imposed organ degeneration, thereby slowing down the rate at which we become progressively unhealthy.”

Funding from the SENS Research Foundation, the National Institute on Aging and the California Institute for Regenerative Medicine helped support this research.

RELATED INFORMATION

• Bioengineers reprogram muscles to combat degeneration (UC Berkeley press release)
• Old muscle gets new pep in UC Berkeley stem cell study (UC Berkeley press release)
• Rejuvenation of aged progenitor cells by exposure to a young systemic environment (Abstract of 2005 study in Nature)

Article

Music and abstract reasoning skills

Music training is far better

than computer instruction

in improving children’s

abstract reasoning skills.

Sound is a nutrient...

Boys are falling behind and dropping out of academics. Region : USA

USA: Our boys are falling behind and dropping out of academics

As boys sink further socially, so too, do they sink academically. A recent Gallup Student Poll suggests that boys have a weaker emotional connection with school as early as fifth grade, and that more than one in four boys are not engaged or actively disengaged in fifth grade.

Some researchers suggest that boys are disengaged and getting lower grades in class because our schools are not “boy-friendly.” In their book, The Rise of Women: The Growing Gender Gap in Education and What It Means for American Schools, Thomas A. DiPrete and Claudia Buchmann, sociology professors at Columbia and Ohio State, state that “Boys involved in extracurricular cultural activities such as music, art, drama, and foreign languages report higher levels of school engagement and get better grades than other boys. But these activities are often denigrated as un-masculine.”

According to the National Center for Educational Statistics, boys and men are falling behind academically and socially:

• Boys are 30 percent more likely than girls to flunk or drop out of school.
• Girls outperform boys academically, from elementary school to graduate school.
• Women receive 60 percent of all bachelor’s degrees now.
• Boys are five times more likely to be labeled with Attention Deficit Hyperactive Disorder (ADHD).

Cognitive and Motor behavior

According to Dr. John P. Murray, “Viewing behavior in media triggers certain areas of the brain that are associated with ‘arousal/attention, detection of threat, episodic memory encoding and retrieval, and motor programming’.”

Murray’s study mapped the amygdala and related brain structures, using functional magnetic resonance imaging to ascertain the neurological changes that resulted from watching violence on television. He concluded that a relationship existed between the chemistry of the brain and violent viewing, which affected both cognitive and motor behavior.

Therefore, when boys are exposed to media violence, it becomes stored in the brain in a manner similar to post traumatic stress disorder memories. 

Exposed to media violence!

 when boys are exposed to media violence, it becomes stored in the brain in a manner similar to post traumatic stress disorder memories. Another study by Dr. Craig A. Anderson involving media violence exposure in youth, found that even short term viewing of violence can increase physical and verbal aggression, aggressive thoughts, and aggressive emotions. In fact, according to Anderson, frequent exposure to media violence in childhood can lead to aggressive behavior later in life, including physical and spousal abuse.

This research on violent viewing and its effects on children have surprisingly uncovered that chemicals, such as cortisol — that change the architecture of the brain, including impulse control — are doing so because children’s brains are actually imitating the violence that they are seeing. In a sense the mind is rehearsing and imitating the aggressive behavior viewed. As a result, aggressive behavior and aggressive responses become an acceptable option later on when children are confronted with conflict. Dr. Murray calls this brain behavior “encoding aggressive scripts,” and states that the posterior cingulate, a part of the brain that holds emotional trauma, stores these neural images and retrieves them in a manner similar to the flashbacks of traumatic memory, present in post-traumatic stress disorder. And, excessive viewing of video games also impacts brain function in a similar manner.

Access to Violence Alters Boys’ Brains

Recently, I had the opportunity to attend TED2014 and I was very excited about what psychologist Phillip Zimbardo had to say. He spoke about how men are failing socially, academically and with women. His TED talk struck a nerve with me.

The debate is on about how we as a nation are failing our boys and men, and many fingers, including Zimbardo’s, are pointing to our technology-driven society (namely violent video games and easy access to pornography) and schools that aren’t as “boy friendly.”

I agree: it is time we step up to the plate and support our boys early on, before they become disengaged men.

Our boys are immersed in technology that is altering their brains.

The shift in our culture toward increased technology time — television, video games, the Internet, and social media — is not without consequence.

Whenever you watch anything on television, your imagination pulls you into what you’re watching. As a result, you react emotionally as if whatever is happening on television is actually happening to you. Consider that the average American youth spends approximately 50 hours per week in front of some sort of screen or another, whether playing video and computer games or watching television. That’s a LOT of screen time, to say the least. Consistent exposure to violent video games, television shows, and movies, as well as pornography, can impact the brain and actually alter its architecture.

According to Dr. John P. Murray, “Viewing behavior in media triggers certain areas of the brain that are associated with ‘arousal/attention, detection of threat, episodic memory encoding and retrieval, and motor programming’.” Murray’s study mapped the amygdala and related brain structures, using functional magnetic resonance imaging to ascertain the neurological changes that resulted from watching violence on television. He concluded that a relationship existed between the chemistry of the brain and violent viewing, which affected both cognitive and motor behavior.

Therefore, when boys are exposed to media violence, it becomes stored in the brain in a manner similar to post traumatic stress disorder memories. Another study by Dr. Craig A. Anderson involving media violence exposure in youth, found that even short term viewing of violence can increase physical and verbal aggression, aggressive thoughts, and aggressive emotions. In fact, according to Anderson, frequent exposure to media violence in childhood can lead to aggressive behavior later in life, including physical and spousal abuse.

This research on violent viewing and its effects on children have surprisingly uncovered that chemicals, such as cortisol — that change the architecture of the brain, including impulse control — are doing so because children’s brains are actually imitating the violence that they are seeing. In a sense the mind is rehearsing and imitating the aggressive behavior viewed. As a result, aggressive behavior and aggressive responses become an acceptable option later on when children are confronted with conflict. Dr. Murray calls this brain behavior “encoding aggressive scripts,” and states that the posterior cingulate, a part of the brain that holds emotional trauma, stores these neural images and retrieves them in a manner similar to the flashbacks of traumatic memory, present in post-traumatic stress disorder. And, excessive viewing of video games also impacts brain function in a similar manner.

According to Dr. Vincent Matthews at Indiana University, “Behavioral studies have shown an increase in aggressive behavior after playing violent video games, and what we show is a physiological explanation for what the behavioral studies are showing.” Dr. Matthews’ research demonstrates brain changes directly related to only two hours of violent viewing daily. The brain changes that Matthew’s group saw were similar to those seen in teens with destructive sociopathic disorders.

Dr. Anderson stated, “The most recent thorough review of the research on media violence, by an expert panel convened by the U.S. surgeon general concluded, ‘Research on violent television, films, video games, and music reveals unequivocal evidence that media violence increases the likelihood of aggressive and violent behavior in both immediate and long-term contexts.’ Hundreds of original empirical studies of the link between media violence and aggression have been conducted and numerous reviews of those studies-both narrative and statistical- have come to the same conclusion.” Further, they cite a finished study by Kaj Bjorkqvist in which he concluded that “even a single exposure increases aggression in the immediate situation.” And longitudinal studies demonstrate that children who played a lot of video games through childhood where more physically aggressive throughout their life.

Our boys are losing critical social skills by being tied to technology.

Throughout my experience as a researcher and educator, and based on the aforementioned scientific research, it stands to reason that the impersonal culture of the internet has the capability of blocking our nation’s boys from fulfilling their share of future leadership potential. True social interaction, necessary for adult success in work and in life, isn’t being taught to these boys because they are immersed in mostly virtual relationships without consequences. In a way, boys who spend too much time interacting only online and through video games stay immature because they don’t get to experience the real consequences of their feelings, thoughts, and actions; they don’t learn how to deal. They’re not learning the social skills one needs to succeed in the world as a functioning adult.

Our boys are falling behind and dropping out of academics

As boys sink further socially, so too, do they sink academically. A recent Gallup Student Poll suggests that boys have a weaker emotional connection with school as early as fifth grade, and that more than one in four boys are not engaged or actively disengaged in fifth grade.

Some researchers suggest that boys are disengaged and getting lower grades in class because our schools are not “boy-friendly.” In their book, The Rise of Women: The Growing Gender Gap in Education and What It Means for American Schools, Thomas A. DiPrete and Claudia Buchmann, sociology professors at Columbia and Ohio State, state that “Boys involved in extracurricular cultural activities such as music, art, drama, and foreign languages report higher levels of school engagement and get better grades than other boys. But these activities are often denigrated as un-masculine.”

According to the National Center for Educational Statistics, boys and men are falling behind academically and socially:
• Boys are 30 percent more likely than girls to flunk or drop out of school.
• Girls outperform boys academically, from elementary school to graduate school.
• Women receive 60 percent of all bachelor’s degrees now.
• Boys are five times more likely to be labeled with Attention Deficit Hyperactive Disorder (ADHD).

What can we do about it?

• If you are the parent of a young boy in elementary or middle school, limit his screen time. Most doctors recommend no more than one or two hours per day. This includes television, cell phones, video games, and tablets.
• Know what your child is watching. Parents must parent, and that means being aware of what happens in the video games he plays and the shows he watches. It is up to you to ensure the screen time your child is exposed to is appropriate.
• Communicate with your child’s school. It is important for parents and teachers to keep open lines of communication, so that you are made aware of any changes your child exhibits at school, and you can address those changes head on before your child gets lost in the shuffle.
• Support your son’s wishes for school participation without judgment or gender bias. Encourage him to participate in music, arts, and theater programs if he shows an interest.
• Practice the empathic process. Set aside time to chat with your kids in the kitchen after school or each night, and allow them to share anything about their day with you openly, without judgment or your immediate reaction. This helps build trust, so that when any issues do come up, you know that they already have the confidence in you to share openly and honestly.
• Engage your child from a young age in play that does not involve technology. Make library, science museum, and museum of natural history visits an important part of your regular family time. Give your child free play time to help develop his imagination and hone his problem solving skills.
• Model strong in-person relationships that are rich with positive, face-to-face interactions.
• Parents should allow plenty of time for free play that does not involve technology from the time children are born. The ability to create, learn, and test boundaries within safe limits helps flex the imagination muscles in children, and real-world understanding.

We may not be able to change our education system or the video game industry overnight, but we do have some control as parents to help ensure our own sons do not fall through the cracks.

Article

COMPLEMENTARY PERSONALITIES

The romantic myth that 'opposites attract' has been around for centuries.

From Beauty and the Beast to the Little Mermaid, many popular fairy tales are centred around couples coming together in spite of their glaring differences.

But according to decades of scientific research, opposites tend to find each other repulsive.

In the mid-1950s, the sociologist Robert Francis Winch argued that, when it comes to our personalities, what matters is not similarity but complementarity.

Based on his studies of spouses, he suggested that individuals would be attracted to others who possess personality traits that they lack.

An assertive woman, for example, would be attracted to a submissive man while an extroverted man would be attracted to an introverted woman.

As it turns out, there is almost no evidence to support this hypothesis. Studies of friends and spouses consistently find that two individuals are more likely to be friends and spouses if they are similar in terms of their personalities.

Violence, The Media And Your Brain

In virtually every aspect of today's entertainment world (TV, movies, video games, music) violence is ubiquitous and often glorified.

Suspension of disbelief is entertaining. Sitting passively and watching “The Dark Knight Rises” or playing Grand Theft Auto is a fun way to relax and forget about real life for a bit. Where’s the harm in that?

The evidence continues to mount that it’s not all good. A study by the Indiana University School of Medicine examined young men and violent media exposure. There were visible alterations in MRI brain scans after only one week of playing a violent video game. In particular, there was a significant decrease in the activation of prefrontal portions of the brain and a greater activation of the amygdala.

Source:

A quick neuroscience lesson: The prefrontal cortex is the so called “thinking part” of the brain which deals with concentration, decision making, self-control and inhibition while the amygdala is part of the limbic system, the so called “emotion center” that serves many emotional functions, but can be the trigger for depression, anger, aggression and impulsive behavior.

To my knowledge this is the first prospective study showing actual brain differences in those that play a violent video game versus those who do not.

Of course, just because the brain has changed does not prove causality. If it were all bad, we would be dealing with millions of aggressive, violent young killers, and that's simply not the case.

But the findings are intriguing and beg the question: Does an activation of the limbic system and an inhibition of the prefrontal cortex predispose to violent behavior? This is a relatively easy proposition to test and I suspect we will see more studies soon.

Other interesting studies:

The Virginia Tech Research Division showed students several non-violent movies, followed by super-violent movies. Results indicated violent films can increase hostile behavior.

The University of Alabama conducted a similar study and obtained similar results. The results also indicated the aggressive behavior didn't occur just after viewing, but remained with the individuals for "quite some time." The study concludes with a caution for parents that immature and/or aggressive children should not have access to violent films.

The Macquarie University Children and Families Research Centre found that children who watch violent movies are more likely to view the world as an unsympathetic, malicious and scary place and that this stimulates aggression. It also suggests children are more likely to exhibit combative behavior while becoming desensitized to violence. Reportedly, the MRI brain scans of children who have viewed film or television violence had a similar look when compared to those who have violently acted out.

For every study, there will always be a naysayer screaming foul. A gory video game or violent TV show can be a great babysitter. This means Junior is more likely to be happy staying at home, supposedly “out of trouble”. Also, globally the video game industry brought in $66 billion in 2012 and 85% percent of these games contain some violence. Of course, money is often the ultimate incentive to maintain the status quo.

Brain changes, aggressive behavior, poor decision making. As the evidence continues to mount, the whole process is reminiscent of when cigarette smoking first became linked to cancer, emphysema and lung disease. Just about everyone sensed it was true, but big money tobacco companies kept funding study after study that all claimed there was just no “proof”.

Fifty years from now, we will all look back and wonder why it took so long -- the evidence was just so overwhelming. In the meantime, lawmakers are currently proposing an increased tax on the sales of violent video games. The money raised would fund mental health programs and research into how to prevent mass shootings.

While researchers offer more and more evidence, the Motion Picture Association of America (MPAA) which represents the six largest (and most profitable) Hollywood studios stepped up recently and announced they would do their part by…… enlarging the font of the R in the ratings of movies. Well, that should solve the problem. Seriously, MPAA?

Denial is a powerful tool. Just like smokers who have a developed rationality on why it’s okay to keep puffing away, many parents/people will take the same stance on media violence with a plethora of reasons as to why it’s really no big deal. We often continue doing things we know aren't good for us, because it's the path of least resistance and heck, everyone else is doing it too, so how bad can it really be?

Source

Λογική

O Αριστοτέλης δεν αρνιόταν το γεγονός ότι ο άνθρωπος διαθέτει από γεννησιμιού του την ικανότητα να σκέφτεται λογικά. Αντίθετα κατά τον Αριστοτέλη, η λογική είναι το βασικότερο χαρακτηριστικό του ανθρώπου. Το μυαλό μας, όμως, είναι εντελώς «αδειανό» ώσπου αρχίζουμε και το τροφοδοτούμε με εμπειρίες. O άνθρωπος, επομένως, δεν έχει «ιδέες» από γεννησιμιού του.

Αυτή ήταν μία από τις κύριες διαφωνίες που είχε ο Αριστοτέλης με τον Πλάτωνα και την Θεωρία των Ιδεών του.

H λέξη «λογική» (όχι όμως και η έννοια) ήταν άγνωστη στην εποχή του Αριστοτέλη. Τη λέξη λογική με τη σημερινή της έννοια τη χρησιμοποίησε αργότερα πρώτος ο Αλέξανδρος ο Αφροδισιεύς (δίδαξε στην Αθήνα περιπατητική φιλοσοφία το 198 έως 211 μ.Χ.)

Η λογική αναδείχθηκε σε επιστήμη από τον Αριστοτέλη. Γι αυτό και ο κορυφαίος Γερμανός φιλόσοφος Καντ είπε ότι «η λογική δεν μπόρεσε να κάνει ούτε ένα βήμα μπροστά από τη λογική που ξέρουμε από την εποχή του Αριστοτέλη».

Πηγή

Changing gut bacteria through diet affects brain function, UCLA study shows

UCLA researchers now have the first evidence that bacteria ingested in food can affect brain function in humans. In an early proof-of-concept study of healthy women, they found that women who regularly consumed beneficial bacteria known as probiotics through yogurt showed altered brain function, both while in a resting state and in response to an emotion-recognition task.

The study, conducted by scientists with the Gail and Gerald Oppenheimer Family Center for Neurobiology of Stress, part of the UCLA Division of Digestive Diseases, and the Ahmanson–Lovelace Brain Mapping Center at UCLA, appears in the current online edition of the peer-reviewed journal Gastroenterology.

The discovery that changing the bacterial environment, or microbiota, in the gut can affect the brain carries significant implications for future research that could point the way toward dietary or drug interventions to improve brain function, the researchers said.

"Many of us have a container of yogurt in our refrigerator that we may eat for enjoyment, for calcium or because we think it might help our health in other ways," said Dr. Kirsten Tillisch, an associate professor of medicine in the digestive diseases division at UCLA's David Geffen School of Medicine and lead author of the study. "Our findings indicate that some of the contents of yogurt may actually change the way our brain responds to the environment. When we consider the implications of this work, the old sayings 'you are what you eat' and 'gut feelings' take on new meaning."

Researchers have known that the brain sends signals to the gut, which is why stress and other emotions can contribute to gastrointestinal symptoms. This study shows what has been suspected but until now had been proved only in animal studies: that signals travel the opposite way as well.

"Time and time again, we hear from patients that they never felt depressed or anxious until they started experiencing problems with their gut," Tillisch said. "Our study shows that the gut–brain connection is a two-way street."

The small study involved 36 women between the ages of 18 and 55. Researchers divided the women into three groups: one group ate a specific yogurt containing a mix of several probiotics — bacteria thought to have a positive effect on the intestines — twice a day for four weeks; another group consumed a dairy product that looked and tasted like the yogurt but contained no probiotics; and a third group ate no product at all.

Functional magnetic resonance imaging (fMRI) scans conducted both before and after the four-week study period looked at the women's brains in a state of rest and in response to an emotion-recognition task in which they viewed a series of pictures of people with angry or frightened faces and matched them to other faces showing the same emotions. This task, designed to measure the engagement of affective and cognitive brain regions in response to a visual stimulus, was chosen because previous research in animals had linked changes in gut flora to changes in affective behaviors.

The researchers found that, compared with the women who didn't consume the probiotic yogurt, those who did showed a decrease in activity in both the insula — which processes and integrates internal body sensations, like those from the gut — and the somatosensory cortex during the emotional reactivity task. 

Further, in response to the task, these women had a decrease in the engagement of a widespread network in the brain that includes emotion-, cognition- and sensory-related areas. The women in the other two groups showed a stable or increased activity in this network.

During the resting brain scan, the women consuming probiotics showed greater connectivity between a key brainstem region known as the periaqueductal grey and cognition-associated areas of the prefrontal cortex. The women who ate no product at all, on the other hand, showed greater connectivity of the periaqueductal grey to emotion- and sensation-related regions, while the group consuming the non-probiotic dairy product showed results in between. 

The researchers were surprised to find that the brain effects could be seen in many areas, including those involved in sensory processing and not merely those associated with emotion, Tillisch said.

The knowledge that signals are sent from the intestine to the brain and that they can be modulated by a dietary change is likely to lead to an expansion of research aimed at finding new strategies to prevent or treat digestive, mental and neurological disorders, said Dr. Emeran Mayer, a professor of medicine (digestive diseases), physiology and psychiatry at the David Geffen School of Medicine at UCLA and the study's senior author.

"There are studies showing that what we eat can alter the composition and products of the gut flora — in particular, that people with high-vegetable, fiber-based diets have a different composition of their microbiota, or gut environment, than people who eat the more typical Western diet that is high in fat and carbohydrates," Mayer said. "Now we know that this has an effect not only on the metabolism but also affects brain function."

The UCLA researchers are seeking to pinpoint particular chemicals produced by gut bacteria that may be triggering the signals to the brain. They also plan to study whether people with gastrointestinal symptoms such as bloating, abdominal pain and altered bowel movements have improvements in their digestive symptoms which correlate with changes in brain response.

Meanwhile, Mayer notes that other researchers are studying the potential benefits of certain probiotics in yogurts on mood symptoms such as anxiety. He said that other nutritional strategies may also be found to be beneficial.

By demonstrating the brain effects of probiotics, the study also raises the question of whether repeated courses of antibiotics can affect the brain, as some have speculated. Antibiotics are used extensively in neonatal intensive care units and in childhood respiratory tract infections, and such suppression of the normal microbiota may have long-term consequences on brain development.

Finally, as the complexity of the gut flora and its effect on the brain is better understood, researchers may find ways to manipulate the intestinal contents to treat chronic pain conditions or other brain related diseases, including, potentially, Parkinson's disease, Alzheimer's disease and autism.

Answers will be easier to come by in the near future as the declining cost of profiling a person's microbiota renders such tests more routine, Mayer said.

The study was funded by Danone Research. Mayer has served on the company's scientific advisory board. Three of the study authors (Denis Guyonnet, Sophie Legrain-Raspaud and Beatrice Trotin) are employed by Danone Research and were involved in the planning and execution of the study (providing the products) but had no role in the analysis or interpretation of the results.

UCLA's Gail and Gerald Oppenheimer Family Center for Neurobiology of Stress, part of the UCLA Division of Digestive Diseases, is an NIH-funded multidisciplinary, translational research program partially supported by philanthropy. Its mission is to identify the role of the brain in health and medical disease. The Center is comprised of several research programs which focus on the interactions of the brain with the digestive, cardiovascular and urological systems, chronic pain and mind brain body interactions.