Obese stomachs tell us diets are doomed to fail

Public release date: 16-Sep-2013 [

Contact: Amanda Page amanda.page@adelaide.edu.au 61-882-225-644 University of Adelaide

The way the stomach detects and tells our brains how full we are becomes damaged in obese people but does not return to normal once they lose weight, according to new research from the University of Adelaide.

Researchers believe this could be a key reason why most people who lose weight on a diet eventually put that weight back on.

In laboratory studies, University of Adelaide PhD student Stephen Kentish investigated the impact of a high-fat diet on the gut’s ability to signal fullness, and whether those changes revert back to normal by losing weight.

The results, published in the International Journal of Obesity, show that the nerves in the stomach that signal fullness to the brain appear to be desensitized after long-term consumption of a high-fat diet.

“The stomach’s nerve response does not return to normal upon return to a normal diet.  This means you would need to eat more food before you felt the same degree of fullness as a healthy individual,” says study leader Associate Professor Amanda Page from the University’s Nerve-Gut Research Laboratory.

“A hormone in the body, leptin, known to regulate food intake, can also change the sensitivity of the nerves in the stomach that signal fullness.  In normal conditions, leptin acts to stop food intake.  However, in the stomach in high-fat diet induced obesity, leptin further desensitizes the nerves that detect fullness.

“These two mechanisms combined mean that obese people need to eat more to feel full, which in turn continues their cycle of obesity.”

Associate Professor Page says the results have “very strong implications for obese people, those trying to lose weight, and those who are trying to maintain their weight loss”.

“Unfortunately, our results show that the nerves in the stomach remain desensitized to fullness after weight loss has been achieved,” she says.

Associate Professor Page says they’re not yet sure whether this effect is permanent or just long-lasting.

“We know that only about 5% of people on diets are able to maintain their weight loss, and that most people who’ve been on a diet put all of that weight back on within two years,” she says.

“More research is needed to determine how long the effect lasts, and whether there is any way – chemical or otherwise – to trick the stomach into resetting itself to normal.”

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This study has been funded by the National Health and Medical Research Council (NHMRC).

Media Contact:

Associate Professor Amanda Page Nerve-Gut Research Laboratory School of Medicine The University of Adelaide Phone: +61 8 8222 5644 amanda.page@adelaide.edu.au

Common Food Supplement Fights Degenerative Brain Disorders : Phosphatidylserine

Common Food Supplement Fights Degenerative Brain Disorders Tuesday, May 21, 2013

Nutritional supplement delays advancement of Parkinson’s and Familial Dysautonomia, TAU researchers discover

Widely available in pharmacies and health stores, phosphatidylserine is a natural food supplement produced from beef, oysters, and soy. Proven to improve cognition and slow memory loss, it’s a popular treatment for older people experiencing memory impairment. Now a team headed by Prof. Gil Ast and Dr. Ron Bochner of Tel Aviv University‘s Department of Human Molecular Genetics has discovered that the same supplement improves the functioning of genes involved in degenerative brain disorders, including Parkinson’s disease and Familial Dysautonomia (FD).

In FD, a rare genetic disorder that impacts the nervous system and appears almost exclusively in the Ashkenazi Jewish population, a genetic mutation prevents the brain from manufacturing healthy IKAP proteins — which likely have a hand in cell migration and aiding connections between nerves — leading to the early degeneration of neurons. When the supplement was applied to cells taken from FD patients, the gene function improved and an elevation in the level of IKAP protein was observed, reports Prof. Ast. These results were replicated in a second experiment which involved administering the supplement orally to mouse populations with FD.

The findings, which have been published in the journal Human Molecular Genetics, are very encouraging, says Prof. Ast. “That we see such an effect on the brain — the most important organ in relation to this disease — shows that the supplement can pass through the blood-brain barrier even when administered orally, and accumulate in sufficient amounts in the brain.”

Slowing the death of nerve cells

Already approved for use as a supplement by the FDA, phosphatidylserine contains a molecule essential for transmitting signals between nerve cells in the brain. Prof. Ast and his fellow researchers decided to test whether the same chemical, which is naturally synthesized in the body and known to boost memory capability, could impact the genetic mutation which leads to FD.

Researchers applied a supplement derived from oysters, provided by the Israeli company Enzymotec, to cells collected from FD patients. Noticing a robust effect on the gene, including a jump in the production of healthy IKAP proteins, they then tested the same supplement on mouse models of FD, engineered with the same genetic mutation that causes the disease in humans.

The mice received the supplement orally, every two days for a period of three months. Researchers then conducted extensive genetic testing to assess the results of the treatment. “We found a significant increase of the protein in all the tissues of the body,” reports Prof. Ast, including an eight-fold increase in the liver and 1.5-fold increase in the brain. “While the food supplement does not manufacture new nerve cells, it probably delays the death of existing ones,” he adds.

Therapeutic potential for Parkinson’s

That the supplement is able to improve conditions in the brain, even when given orally, is a significant finding, notes Prof. Ast. Most medications enter the body through the blood stream, but are incapable of breaking through the barrier between the blood and the brain.

In addition, the researchers say the supplement’s positive effects extend beyond the production of IKAP. Not only did phosphatidylserine impact the gene associated with FD, but it also altered the level of a total of 2400 other genes — hundreds of which have been connected to Parkinson’s disease in previous studies.

The researchers believe that the supplement may have a beneficial impact on a number of degenerative diseases of the brain, concludes Prof. Ast, including a major potential for the development of new medications which would help tens of millions of people worldwide suffering from these devastating diseases

Markets erode moral values

Contact: Dr. Armin Falk armin.falk@uni-bonn.de 49-228-739-240 University of Bonn

Researchers from the Universities of Bamberg and Bonn present causal evidence on how markets affect moral values

Many people express objections against child labor, exploitation of the workforce or meat production involving cruelty against animals. At the same time, however, people ignore their own moral standards when acting as market participants, searching for the cheapest electronics, fashion or food. Thus, markets reduce moral concerns. This is the main result of an experiment conducted by economists from the Universities of Bonn and Bamberg. The results are presented in the latest issue of the renowned journal “Science“.

Prof. Dr. Armin Falk from the University of Bonn and Prof. Dr. Nora Szech from the University of Bamberg, both economists, have shown in an experiment that markets erode moral concerns. In comparison to non-market decisions, moral standards are significantly lower if people participate in markets.

In markets, people ignore their individual moral standards

“Our results show that market participants violate their own moral standards,” says Prof. Falk. In a number of different experiments, several hundred subjects were confronted with the moral decision between receiving a monetary amount and killing a mouse versus saving the life of a mouse and foregoing the monetary amount. “It is important to understand what role markets and other institutions play in moral decision making. This is a question economists have to deal with,” says Prof. Szech.

“To study immoral outcomes, we studied whether people are willing to harm a third party in exchange to receiving money. Harming others in an intentional and unjustified way is typically considered unethical,” says Prof. Falk. The animals involved in the study were so-called “surplus mice”, raised in laboratories outside Germany. These mice are no longer needed for research purposes. Without the experiment, they would have all been killed. As a consequence of the study many hundreds of young mice that would otherwise all have died were saved. If a subject decided to save a mouse, the experimenters bought the animal. The saved mice are perfectly healthy and live under best possible lab conditions and medical care.

Simple bilateral markets affect moral decisions

A subgroup of subjects decided between life and money in a non-market decision context (individual condition). This condition allows for eliciting moral standards held by individuals. The condition was compared to two market conditions in which either only one buyer and one seller (bilateral market) or a larger number of buyers and sellers (multilateral market) could trade with each other. If a market offer was accepted a trade was completed, resulting in the death of a mouse. Compared to the individual condition, a significantly higher number of subjects were willing to accept the killing of a mouse in both market conditions. This is the main result of the study. Thus markets result in an erosion of moral values. “In markets, people face several mechanisms that may lower their feelings of guilt and responsibility,” explains Nora Szech. In market situations, people focus on competition and profits rather than on moral concerns. Guilt can be shared with other traders. In addition, people see that others violate moral norms as well.

“If I don’t buy or sell, someone else will.”

In addition, in markets with many buyers and sellers, subjects may justify their behavior by stressing that their impact on outcomes is negligible. “This logic is a general characteristic of markets,” says Prof. Falk. Excuses or justifications appeal to the saying, “If I don’t buy or sell now, someone else will.” For morally neutral goods, however, such effects are of minor importance. Nora Szech explains: “For goods without moral relevance, differences in decisions between the individual and the market conditions are small. The reason is simply that in such cases the need to share guilt or excuse behavior is absent.”

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Publication: Morals and Markets, Science, DOI: 10.1126/science.1231566

Contact:

Prof. Dr. Armin Falk University of Bonn Institute for Applied Microeconomics Ph.: +49 228 739 240 Email: armin.falk@uni-bonn.de

Prof. Dr. Nora Szech University of Bamberg Department of Economics Ph.: +49 951 863-2637 Email: nora.szech@uni-bamberg.de

Why your brain tires when exercising : Excess Serotonin shuts down the brain causing fatigue

 

A marathon runner approaches the finishing line, but suddenly the sweaty athlete collapses to the ground. Everyone probably assumes that this is because he has expended all energy in his muscles. What few people know is that it might also be a braking mechanism in the brain which swings into effect and makes us too tired to continue. What may be occurring is what is referred to as ‘central fatigue’.

“Our discovery is helping to shed light on the paradox which has long been the subject of discussion by researchers. We have always known that the neurotransmitter serotonin is released when you exercise, and indeed, it helps us to keep going. However, the answer to what role the substance plays in relation to the fact that we also feel so exhausted we have to stop has been eluding us for years. We can now see it is actually a surplus of serotonin that triggers a braking mechanism in the brain. In other words, serotonin functions as an accelerator but also as a brake when the strain becomes excessive,” says Associate Professor Jean-François Perrier from the Department of Neuroscience and Pharmacology, who has spearheaded the new research.

Help in the battle against doping

Jean-François Perrier hopes that mapping the mechanism that prompts central fatigue will be useful in several ways. Central fatigue is a phenomenon which has been known for about 80 years; it is a sort of tiredness which, instead of affecting the muscles, hits the brain and nervous system. By conducting scientific experiments, it is possible to observe and measure that the brain sends insufficient signals to the muscles to keep going, which in turn means that we are unable to keep performing. This makes the mechanism behind central fatigue an interesting area in the battle against doping, and it is for this reason that Anti Doping Danmark has also helped fund the group’s research.

“In combating the use of doping, it is crucial to identify which methods athletes can use to prevent central fatigue and thereby continue to perform beyond what is naturally possible. And the best way of doing so is to understand the underlying mechanism,” says Jean-François Perrier.

Developing better drugs

The brain communicates with our muscles using so-called motoneurons (see fact box). In several diseases, motoneurons are hyperactive. This is true, for example, of people suffering from spasticity and cerebral palsy, who are unable to control their movements. Jean-François Perrier therefore hopes that, in the long term, this new knowledge can also be used to help develop drugs against these symptoms and to find out more about the effects of antidepressants.

“This new discovery brings us a step closer to finding ways of controlling serotonin. In other words, whether it will have an activating effect or trigger central fatigue. It is all about selectively activating the receptors which serotonin attaches to,” explains Jean-François Perrier.

“For selective serotonin re-uptake inhibitor (SSRI) drugs which are used as antidepressants, we can possibly help explain why those who take the drugs often feel more tired and also become slightly clumsier than other people. What we now know can help us develop better drugs,” concludes Jean-François Perrier.

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The new results have just been published in the renowned scientific journal PNAS. Read the article ‘Serotonin spillover onto the axon initial segment of motoneurons induces central fatigue by inhibiting action potential initiation’. DOI: 10.1073 PNAS article #: 201216150.

CONTACT

Associate Professor Jean-François Perrier Department of Neuroscience and Pharmacology University of Copenhagen Telephone: +45 23 81 27 46 E-mail: Perrier@sund.ku.dk Skype: jfoboulot

Jean-François Perrier will be travelling until March 11. If you cannot reach him by phone, send him an email and he will call you back.

 

Communications Officer

Louise Graa Christensen Faculty of Health and Medical Sciences University of Copenhagen Mobile: +45 24 34 03 22 E-mail: louise.christensen@sund.ku.dk

FACTS

About the research

In addition to Jean-François Perrier, the research team responsible for mapping the braking mechanism includes Florence Cotel and two researchers from the University of Oxford (Stephanie Cragg and Richard Exley). In order to be able to study the motoneurons, the researchers have studied large American turtles. This is because the adult turtle’s spinal marrow, where the motoneurons are found, is accessible to experimentation but also resemble conditions in humans. It is in precisely this respect that that results obtained from  cross-sections of the spinal marrow in turtles, help researchers to understand central fatigue in the nervous system of humans.

Masterful motoneurons

In the human brain there are about 100 billion nerve cells, or neurons. Each neuron consists of a cell body with dendrites and a nerve fiber called the axon, and they communicate with one another via synapses. Nerve cells use nerve impulses to send signals with the axon from the cell body to the nerve ends, which form synapses with the dendrites of the receiving cell.

A special kind of neuron, the motoneurons, are extremely important as they are responsible for ensuring contact between the brain and the muscles. Every time a motoneuron sends impulses to the muscles, it leads to the contraction of the muscle fibres contacted and thus a movement. In order to control the body’s movements, the brain has to be able to control the impulse activity in groups of motoneurons so they are activated in the right sequence and to the right degree. It is here that serotonin plays a role as one of the neurotransmitters which are released from the synapses during the brain’s ingenious control of the motoneurons and thereby our patterns of movement.

Serotonin and central fatigue

Serotonin is well known for being involved in many different human functions: Appetite, sleep, sex and motor control. Serotonin is released as soon as you start moving, and the more you move, the more serotonin is released. In other words, serotonin functions as an accelerator for movement and makes the motoneurons more active. However, when large amounts of serotonin are released, it causes a glut at the synapses through which the neurons communicate. This means that the serotonin starts binding with the receptors lying outside the synapses. Some of these receptors sit at the initial part of the axon, i.e. where nerve impulses are formed. And when the serotonin activates these receptors, the nerve impulse is obstructed, the result being that the muscle contraction is weakened and fatigue occurs

Fish Oil Helps Heal Bed Sores of the Critically Ill

December 4, 2012

Tel Aviv University research finds a 20-25 percent reduction in pressure ulcers with a fish oil enriched diet

Chock-full of Omega-3 fatty acids and antioxidants, fish oil can help lower blood pressure, reduce inflammation in the skin and joints, and promote healthy fetal development. Now a Tel Aviv University researcher has found that it has a positive effect on bedsores, too.

A common problem in critically ill patients, bedsores result from constant pressure on the skin and underlying tissue due to prolonged sitting or lying down. Painful and prone to infection, the pressure ulcers need to be healed, says Prof. Pierre Singer of the Sackler Faculty of Medicine. With Ph.D. candidate Miriam Theilla at the Rabin Medical Center, he designed a randomized experiment to determine the impact of dietary fish oil supplements on the bedsores of critically ill patients.

After a three week period of adding eight grams of fish oil to their patients’ daily diet, the researchers found not only a significant lessening of pain and discomfort from bedsores — a 20 to 25 percent improvement, according to the Pressure Ulcer Scale for Healing — but also a more efficient immune system and a reduction to inflammation throughout the body. The results were reported in the British Journal of Nutrition and the American Journal of Critical Care.

Boosting the immune system

Inspired by the results of a previous study showing that dietary fish oil supplements for critically ill patients raised oxygen levels in body tissues, Prof. Singer and his fellow researchers sought to determine whether the supplement could also help heal bedsores, which are also formed by a lack of oxygen, reduced blood flow, and skin wetness.

To test this theory, the researchers developed a randomized study with 40 critically ill patients. Half the patients were given standard hospital diets, and the rest had a daily addition of eight grams of fish oil added in their food. After a three-week period, the patients in the fish oil group had an average of 20 to 25 percent improvement in the healing of their bedsores compared to the control group.

Beyond the size of the bedsores, the researchers also measured different immune parameters and found that the patients in the fish oil group had experienced a boost in their immune system and a reduction in swelling. “We saw a modification in the expression of a group of molecules associated with directing leukocytes, or white blood cells, in the direction of the wound, which could explain the improved healing,” explains Prof. Singer. In addition, researchers noted a significant decrease in the amount of C-reactive protein in the blood, which is associated with inflammation and linked to viral and bacterial infections, rheumatic diseases, tissue injury, and necrosis.

Natural pain management?

Next, Prof. Singer and his fellow researchers plan to explore the use of fish oil as a method of natural pain management. By measuring the intensity of pain experience in post-surgical patients who have undergone either knee or hip replacements and comparing it to the amount of fish oil the patient has received, they hope to determine whether the nutrient-rich oil can also reduce their patients’ suffering.

Increasing Fertility Threefold ( DHEA )

2010 study posted for filing

 

TAU finds anti-aging supplement is a fountain of hope for would-be mothers

 

 

According to the American Pregnancy Association, six million women a year deal with infertility. Now, a Tel Aviv University study is giving new hope to women who want to conceive — in the form of a pill they can find on their drugstore shelves right now.

 

Prof. Adrian Shulman of Tel Aviv University’s Sackler Faculty of Medicine and the Meir Medical Center has found a statistical connection between the over-the-counter vitamin supplement DHEA, used to counter the effects of aging, and successful pregnancy rates in women undergoing treatment for infertility.

 

In the first controlled study on the effects of the supplement, Prof. Shulman found that women being treated for infertility who also received supplements of DHEA were three times more likely to conceive than women being treated without the additional drug. The results were recently published in AYALA, the journal of the Israeli Fertility Association.

 

A natural supplement to fertility treatments

 

After hearing anecdotal evidence from his patients and the medical community on the benefits of combining fertility treatments with DHEA, a supplement marketed as an anti-aging drug around the world, Prof. Shulman decided to put this old wives’ tale to the statistical test.

 

He and his fellow researchers conducted a study in which a control group of women received treatment for poor ovulation, and another group received the same treatment with the addition of the DHEA supplement. The latter group took 75mg of the supplement daily for 40 days before starting fertility treatments, and continued for up to five months.

 

Not only were women who combined infertility treatment with DHEA more likely to conceive, the researchers discovered, they were also more likely to experience a healthy pregnancy and delivery.

 

“In the DHEA group, there was a 23% live birth rate as opposed to a 4% rate in the control group,” explains Shulman. “More than that, of the pregnancies in the DHEA group, all but one ended in healthy deliveries.”

 

Making grade-A eggs?

 

Shulman believes that women who are finding little success with their current fertility treatments could look to DHEA to improve their chances of conceiving. “We recommend that women try this DHEA treatment, in conjunction with fertility treatments, for four to five months,” says Prof. Shulman. It could also be used as a regular “vitamin” for women who have already conceived and are pregnant, but more research would need to be done on the compound to determine its effects, says Prof. Shulman.

 

DHEA, for 5-Dehydroepiandrosterone (5-DHEA), is a naturally-occurring steroid found in the brain, which plays an important biological role in humans and other mammals. Produced in the adrenal glands, it is also synthesized in the brain. The pharmaceutical version of this molecule is known as Prastera, Prasterone, Fidelin and Fluasterone, and identical generics are widely available over the counter in the United States without a prescription. Women interested in using DHEA to conceive, however, should consult their practitioner first, suggests Prof. Shulman, a gynecologist and director of the IVF Unit of the Obstetric and Gynecology Department at Meir Medical Center.

 

While studies on the effects of DHEA are far from complete — his test group only included around 20 women — Prof. Shulman hopes that further research will unlock the secrets of why the supplement aids in successful conception in women with an otherwise poor response to fertility treatments. “We need to look into what the drug actually does to make the body more fertile,” he says. “It could be affecting components such as the quality of the eggs or the follicles.”

Going with Your Gut: Decisions based on instinct have surprisingly positive outcomes

Thursday, November 8, 2012

Decisions based on instinct have surprisingly positive outcomes, TAU researcher finds

Decision-making is an inevitable part of the human experience, and one of the most mysterious. For centuries, scientists have studied how we go about the difficult task of choosing A or B, left or right, North or South — and how both instinct and intellect figure into the process. Now new research indicates that the old truism “look before you leap” may be less true than previously thought.

In a behavioral experiment, Prof. Marius Usher of Tel Aviv University‘s School of Psychological Sciences and his fellow researchers found that intuition was a surprisingly powerful and accurate tool. When forced to choose between two options based on instinct alone, the participants made the right call up to 90 percent of the time.

The results of their study were recently published in the journal PNAS.

Value-added thinking

Prof. Marius Usher
Prof. Marius Usher

Even at the intuitive level, an important part of the decision-making process is the “integration of value” — that is, taking into account the positive and negative factors of each option to come up with an overall picture, explains Prof. Usher. One weighs the strengths and weaknesses of different apartments for rent or applicants for a job. Various relevant criteria contribute to the decision-making process.

“The study demonstrates that humans have a remarkable ability to integrate value when they do so intuitively, pointing to the possibility that the brain has a system that specializes in averaging value,” Prof. Usher says. This could be the operational system on which common decision-making processes are built.

In order to get to the core of this system, Prof. Usher designed an experiment to put participants through a carefully controlled decision-making process. On a computer screen, participants were shown sequences of pairs of numbers in quick succession. All numbers that appeared on the right of the screen and all on the left were considered a group; each group represented returns on the stock market.

Participants were asked to choose which of the two groups of numbers had the highest average. Because the numbers changed so quickly — two to four pairs were shown every second — the participants were unable to memorize the numbers or do proper mathematical calculations, explains Prof. Usher. To determine the highest average of either group, they had to rely on “intuitive arithmetic.”

Doing the math

The participants were able to calculate the different values accurately at exceptional speed, the researchers found. They were also able to process large amounts of data — in fact, their accuracy increased in relation to the amount of data they were presented. When shown six pairs of numbers, for example, the participants chose accurately 65 percent of the time. But when they were shown 24 pairs, the accuracy rate grew to about 90 percent.

Intuitively, the human brain has the capacity to take in many pieces of information and decide on an overall value, says Prof. Usher. He says that gut reactions can be trusted to make a quality decision — a conclusion supported by his earlier work with Prof. Dan Zakay and Dr. Zohar Rusou published in Frontiers in Cognitive Science.

Risky behavior

Of course, intuition is also subject to certain biases, explains Prof. Usher, and leads to more risks — risks that people are willing to take. That was shown when the researchers engaged participants in tests that measured their risk-taking tendencies, and were surprised to discover that the majority of the participants didn’t play it safe. When faced with a choice between two sets of numbers with the same average, one with a narrow distribution, such as 45 and 55, and another with a broad distribution, such as 70 and 30, people were swayed by the large numbers and took a chance on the broadly distributed numbers rather than making the “safe” choice.

Although this work was based on a behavioral experiment, Prof. Usher says that an interesting next step could be to measure brain activity throughout the task in an attempt to uncover the physiological aspects of value integration.

Activating the ‘mind’s eye’ — sounds, instead of eyesight can be alternative vision ( can actually “see” and describe objects and even identify letters and words )

Contact: Jerry Barach
jerryb@savion.huji.ac.il
972-258-82904
The Hebrew University of Jerusalem

Jerusalem, Nov. 7, 2012 — Common wisdom has it that if the visual cortex in the brain is deprived of visual information in early infanthood, it may never develop properly its functional specialization, making sight restoration later in life almost impossible.

Scientists at the Hebrew University of Jerusalem and in France have now shown that blind people – using specialized photographic and sound equipment – can actually “see” and describe objects and even identify letters and words.

The new study by a team of researchers, led by Prof. Amir Amedi of the Edmond and Lily Safra Center for Brain Sciences and the Institute for Medical Research Israel-Canada at the Hebrew University and Ph.D. candidate Ella Striem-Amit, has demonstrated how this achievement is possible through the use of a unique training paradigm, using sensory substitution devices (SSDs).

SSDs are non-invasive sensory aids that provide visual information to the blind via their existing senses. For example, using a visual-to-auditory SSD in a clinical or everyday setting, users wear a miniature camera connected to a small computer (or smart phone) and stereo headphones.

The images are converted into “soundscapes,” using a predictable algorithm, allowing the user to listen to and then interpret the visual information coming from the camera. The blind participants using this device reach a level of visual acuity technically surpassing the world-agreed criterion of the World Health Organization (WHO) for blindness, as published in a previous study by the same group.

The resulting sight, though not conventional in that it does not involve activation of the ophthalmological system of the body, is no less visual in the sense that it actually activates the visual identification network in the brain.

The study shows that following a dedicated (but relatively brief) 70 hours of unique training paradigm developed in the Amedi lab, the blind people could easily use SSDs to characterize images into object categories, such as images of faces, houses, body shapes, everyday objects and textures. They could also identify even more complex everyday objects — locating people’s positions, identifying facial expressions, and even reading letters and words (for demos, movies and further information: http://brain.huji.ac.il/).

These unprecedented behavioral results are reported in the current issue of the prestigious neuroscience journal, Neuron.

The Hebrew University study went on further to actually test what happens in the brain when the blind learn to see with sounds. Specifically, the group tested the ability of this high-acuity vision to activate the supposedly dormant visual cortex of the blind, even though it was taught to process the visual images through sounds only in adulthood.

Prof. Amedi, and Ella Striem-Amit used functional magnetic resonance imaging (fMRI) to measure the neural activity of people blind from birth as they “saw” — using the SSD — high-resolution images of letters, faces, houses, everyday objects and body-shapes. Surprisingly, not only was their visual cortex activated by the sounds, their brain showed selectivity for visual categories which characterize the normally developing, sighted brain.

A specific part of the brain, known as the Visual Word Form Area, or VWFA — that was first discovered in sighted people by Profs. Laurent Cohen and Stanislas Dehaene of Pitie-Salpétriere Hospital-INSERM-CEA, of France, co-authors of the current article — is normally very selective.

In sighted people, it has a role in reading, and is activated by seeing and reading letters more than by any other visual object category. Astonishingly, the same was found in this area in people deprived of sight. Their VWFA, after only tens of hours of training in SSD use, showed more activation for letters than for any of the other visual categories tested.

In fact, the VWFA was so plastic to change, that it showed increased activation for SSD letters after less than two hours of training by one of the study participants.

“The adult brain is more flexible that we thought,” says Prof. Amedi. In fact, this and other recent research from various groups have demonstrated that multiple brain areas are not specific to their input sense (vision, audition or touch), but rather to the task, or computation they perform, which may be computed with various modalities. (This information was summarized in a recent review by the Amedi research group published in the journal Current Directions in Neurology.)

All of this suggests that in the blind, brain areas might potentially be “awakened” to processing visual properties and tasks even after years or maybe even lifelong blindness, if the proper technologies and training approaches are used, says Amedi.

The findings also give hope that reintroduced input into the visual centers of the blind brain could potentially restore vision, and that SSDs might be useful for visual rehabilitation.

“SSDs might help blind or visually-impaired individuals learn to process complex images, as done in this study, or they might be used as sensory interpreters that provide high-resolution, supportive, synchronous input to a visual signal arriving from an external device such as bionic eyes” says Prof. Amedi.

Weizmann Institute scientists observe as humans learn to sense like a rat, with ”whiskers”

Rats use a sense that humans don’t: whisking. They move their facial whiskers back and forth about eight times a second to locate objects in their environment. Could humans acquire this sense? And if they can, what could understanding the process of adapting to new sensory input tell us about how humans normally sense? At the Weizmann Institute, researchers explored these questions by attaching plastic “whiskers” to the fingers of blindfolded volunteers and asking them to carry out a location task. The findings, which recently appeared in the Journal of Neuroscience, have yielded new insight into the process of sensing, and they may point to new avenues in developing aids for the blind.
The scientific team, including Drs. Avraham Saig and Goren Gordon, and Eldad Assa in the group of Prof. Ehud Ahissar and Dr. Amos Arieli, all of the Neurobiology Department attached a “whisker” – a 30 cm-long elastic “hair” with position and force sensors on its base – to the index finger of each hand of a blindfolded subject. Then two poles were placed at arm’s distance on either side and slightly to the front of the seated subject, with one a bit farther back than the other. Using just their whiskers, the subjects were challenged to figure out which pole – left or right – was the back one. As the experiment continued, the displacement between front and back poles was reduced, up to the point when the subject could no longer distinguish front from back.
On the first day of the experiment, subjects picked up the new sense so well that they could correctly identify a pole that was set back by only eight cm. An analysis of the data revealed that the subjects did this by figuring the spatial information from the sensory timing. That is, moving their bewhiskered hands together, they could determine which pole was the back one because the whisker on that hand made contact earlier.
When they repeated the testing the next day, the researchers discovered that the subjects had improved their whisking skills significantly: The average sensory threshold went down to just three cm, with some being able to sense a displacement of just one cm. Interestingly, the ability of the subjects to sense time differences had not changed over the two days. Rather, they had improved in the motor aspects of their whisking strategies: Slowing down their hand motions – in effect lengthening the delay time – enabled them to sense a smaller spatial difference.
Saig: “We know that our senses are linked to muscles, for example ocular and hand muscles. In order to sense the texture of cloth, for example, we move our fingers across it, and to seeing stationary object, our eyes must be in constant motion. In this research, we see that changing our physical movements alone – without any corresponding change in the sensitivity of our senses – can be sufficient to sharpen our perception.”
Based on the experiments, the scientists created a statistical model to describe how the subjects updated their “world view” as they acquired new sensory information – up to the point at which they were confident enough to rely on that sense. The model, based on principles of information processing, could explain the number of whisking movements needed to arrive at the correct answer, as well as the pattern of scanning the subjects employed – a gradual change from long to short movements. With this strategy, the flow of information remains constant. “The experiment was conducted in a controlled manner, which allowed us direct access to all the relevant variables: hand motion, hand-pole contact and the reports of the subjects themselves,” says Gordon. “Not only was there a good fit between the theory and the experimental data, we obtained some useful quantitative information on the process of active sensing.”
“Both sight and touch are based on arrays of receptors that scan the outside world in an active manner,” says Ahissar, “Our findings reveal some new principles of active sensing, and show us that activating a new artificial sense in a ‘natural’ way can be very efficient.” Arieli adds: “Our vision for the future is to help blind people ‘see’ with their fingers. Small devices that translate video to mechanical stimulation, based on principles of active sensing that are common to vision and touch, could provide an intuitive, easily used sensory aid.”

Prof. Ehud Ahissar’s research is supported by the Murray H. and Meyer Grodetsky Center for Research of Higher Brain Functions; the Jeanne and Joseph Nissim Foundation for Life Sciences Research; the Kahn Family Research Center for Systems Biology of the Human Cell; Lord David Alliance, CBE; the Berlin Family Foundation; Jack and Lenore Lowenthal, Brooklyn, NY; Research in Memory of Irving Bieber, M.D. and Toby Bieber, M.D.; the Harris Foundation for Brain Research; and the Joseph D. Shane Fund for Neurosciences. Prof. Ahissar is the incumbent of the Helen Diller Family Professorial Chair in Neurobiology.

Near-death experiences occur when the soul leaves the nervous system and enters the universe, claim two quantum physics experts

  • Ground-breaking theory holds that quantum substances  form the soul
  • They are  part of the fundamental structure of the universe

By Damien Gayle

PUBLISHED:05:38 EST, 30  October 2012| UPDATED:06:26 EST, 30 October 2012

Life after death: Dr Stuart Hameroff, Professor Emeritus at the University of Arizona, advanced the theory on a television documentaryLife after death: Dr Stuart Hameroff, Professor Emeritus  at the University of Arizona, advanced the theory on a television  documentary

A near-death experience happens when quantum  substances which form the soul leave the nervous system and enter the universe  at large, according to a remarkable theory proposed by two eminent scientists.

According to this idea, consciousness is a  program for a quantum computer in the brain which can persist in the universe  even after death, explaining the perceptions of those who have near-death  experiences.

Dr Stuart Hameroff, Professor Emeritus at the  Departments of Anesthesiology and Psychology and the Director of the Centre of  Consciousness Studies at the University of Arizona, has advanced the  quasi-religious theory.

It is based on a quantum theory of consciousness he and British physicist Sir Roger Penrose have developed which holds that the essence of our soul is contained inside structures called microtubules within brain cells.

They have argued that our experience of  consciousness is the result of quantum gravity effects in these microtubules, a  theory which they dubbed orchestrated objective reduction (Orch-OR).

Thus it is held that our souls are more than  the interaction of neurons in the brain. They are in fact constructed from the  very fabric of the universe – and may have existed since the beginning of  time.

The concept is similar to the Buddhist and  Hindu belief that consciousness is an integral part of the universe – and indeed  that it is really all there may be, a position similar to Western philosophical  idealism.

With these beliefs, Dr Hameroff holds that in  a near-death experience the microtubules lose their quantum state, but the  information within them is not destroyed. Instead it merely leaves the body and  returns to the cosmos.

Shocked back to life: The theory holds that when patients have a near death experience their quantum soul is released from the body and re-enters the cosmos, before returning when they are revivedShocked back to life: The theory holds that when  patients have a near death experience their quantum soul is released from the  body and re-enters the cosmos, before returning when they are revived

Dr Hameroff told the Science Channel’s  Through the Wormhole documentary: ‘Let’s say the heart stops beating, the blood  stops flowing, the microtubules lose their quantum state.

‘The quantum information within the  microtubules is not destroyed, it can’t be destroyed, it just distributes and  dissipates to the universe at large.

‘If the patient is resuscitated, revived,  this quantum information can go back into the microtubules and the patient says  “I had a near death experience”.’

He adds: ‘If they’re not revived, and the  patient dies, it’s possible that this quantum information can exist outside the  body, perhaps indefinitely, as a soul.’

Evidence: Dr Hameroff believes new findings about the role quantum physics plays in biological processes, such as the navigation of birds, will one day prove his theoryEvidence: Dr Hameroff believes new findings about the  role quantum physics plays in biological processes, such as the navigation of  birds, will one day prove his theory

The Orch-OR theory has come in for heavy  criticism by more empirically minded thinkers and remains controversial among  the scientific community.

MIT physicist Max Tegmark is just one of the  many scientists to have challenged it, in a 2000 paper that is widely cited by  opponents, the Huffington Post reports.

Nevertheless, Dr Hameroff believes that  research in to quantum physics is beginning to validate Orch-Or, with quantum  effects recently being shown to support many important biological processes,  such as smell, bird navigation and photosynthesis

Read more: http://www.dailymail.co.uk/sciencetech/article-2225190/Can-quantum-physics-explain-bizarre-experiences-patients-brought-brink-death.html#ixzz2Aq1eoxLj Follow us: @MailOnline on Twitter | DailyMail on Facebook

‘Blue’ Light Could Help Teenagers Combat Stress

A new study shows that exposure to morning short-wavelength “blue” light has the potential to help sleep-deprived adolescents prepare for the challenges of the day and deal with stress, more so than dim light. (Credit: © Beboy / Fotolia)

ScienceDaily (Oct. 22, 2012) — Adolescents can be chronically sleep deprived because of their inability to fall asleep early in combination with fixed wakeup times on school days. According to the CDC, almost 70 percent of school children get insufficient sleep — less than 8 hours on school nights. This type of restricted sleep schedule has been linked with depression, behavior problems, poor performance at school, drug use, and automobile accidents. A new study from the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute shows that exposure to morning short-wavelength “blue” light has the potential to help sleep-deprived adolescents prepare for the challenges of the day and deal with stress, more so than dim light.

The study was a collaboration between Associate Professor and Director of the LRC Light and Health Program Mariana Figueiro and LRC Director and Professor Mark S. Rea. Results of the study were recently published in the open access International Journal of Endocrinology.

Levels of cortisol, a hormone produced by the adrenal gland, follow a daily 24-hour rhythm. Cortisol concentrations are low throughout the day reaching a broad minimum in the evening before rising slowly again throughout the night. In addition to this gradual elevation of cortisol at night, cortisol levels rise sharply within the first 30 to 60 minutes after waking. This is known as the cortisol awakening response (CAR). In nocturnal animals, the cortisol spike occurs at night, at the start of activity. It appears to be associated with the time of transition from rest to activity, upon waking. A high CAR has been associated with better preparedness for stressful and challenging activities.

“The present results are the first to show that low levels of short-wavelength light enhance CAR in adolescents who were restricted from sleep,” said Figueiro. “Morning light exposure may help to wake up the body when it is time to be active, thus preparing individuals for any environmental stress they might experience.”

Short-wavelength light has been shown to maximally suppress production of nocturnal melatonin and phase shift the timing of the biological clock. The effect of short-wavelength light on other biomarkers has not been widely studied.

The study included three overnight sessions, at least one week apart. All participants wore a Dimesimeter on a wrist band to measure light exposure and to verify the regularity of their activity/rest periods during the three-week study. The Dimesimeter is a small calibrated light meter device developed by the LRC that continuously records circadian light and activity levels. During the study, adolescents aged 12 to 17 years went to sleep at 1:30 a.m. and woke up at 6:00 a.m., a 4.5-hour sleep opportunity. Each week, participants either experienced morning short-wavelength blue light (40 lux of 470-nanometer light) or remained in dim light.

“We found that exposure to short-wavelength blue light in the morning significantly enhances CAR in sleep deprived adolescents, more so than dim light,” said Rea. “Morning exposure to short-wavelength light may be a simple, yet practical way to better prepare adolescents for the challenges of the day.”

 

http://www.sciencedaily.com/releases/2012/10/121022112847.htm

TAU Researcher Says Plants Can See, Smell, Feel, and Taste

Re-posted for Filing

Monday, July 30, 2012

Unlocking the secrets of plant genetics could lead to breakthroughs in cancer research and food security

Increasingly, scientists are uncovering surprising biological connections between humans and other forms of life. Now a Tel Aviv University researcher has revealed that plant and human biology is much closer than has ever been understood — and the study of these similarities could uncover the biological basis of diseases like cancer as well as other “animal” behaviors.

In his new book What a Plant Knows (Farrar, Straus and Giroux) and his articles in Scientific American, Prof. Daniel Chamovitz, Director of TAU’s Manna Center for Plant Biosciences, says that the discovery of similarities between plants and humans is making an impact in the scientific community. Like humans, Prof. Chamovitz says, plants also have “senses” such as sight, smell, touch, and taste.

Ultimately, he adds, if we share so much of our genetic makeup with plants, we have to reconsider what characterizes us as human.

These findings could prompt scientists to rethink what they know about biology, says Prof. Chamovitz, pointing out that plants serve as an excellent model for experiments on a cellular level. This research is also crucial to food security, he adds, noting that knowledge about plant genetics and how plants sense and respond to their environment is central to ensuring a sufficient food supply for the growing population — one of the main goals of the Manna Center.

http://www.aftau.org/site/News2/1811415631?page=NewsArticle&id=17013&news_iv_ctrl=-1

NTU-led research probes potential link between cancer and a common chemical in consumer products

study led by a group of Nanyang Technological University (NTU) researchers has found that a chemical commonly used in consumer products can potentially cause cancer.

The chemical, Zinc Oxide, is used to absorb harmful ultra violet light. But when it is turned into nano-sized particles, they are able to enter human cells and may damage the cells’ DNA. This in turn activates a protein called p53, whose duty is to prevent damaged cells from multiplying and becoming cancerous. However, cells that lack p53 or do not produce enough functional p53 may instead develop into cancerous cells when they come into contact with Zinc Oxide nanoparticles.

The study is led by Assistant Professor Joachim Loo, 34, and Assistant Professor Ng Kee Woei, 37, from NTU’s School of Materials Science and Engineering. They worked with Assistant Professor David Leong, 38, from the Department of Chemical and Biomolecular Engineering, National University of Singapore, a joint senior author of this research paper.

The findings suggest that companies may need to reassess the health impact of nano-sized Zinc Oxide particles used in everyday products. More studies are also needed on the use and concentration levels of nanomaterials in consumer products, how often a consumer uses them and in what quantities.

“Currently there is a lack of information about the risks of the nanomaterials used in consumer products and what they can pose to the human body. This study points to the need for further research in this area and we hope to work with the relevant authorities on this,” said Asst Prof Loo.

The groundbreaking research findings were published in this month’s edition of Biomaterials, one of the world’s top journals in the field of biomaterials research. The breakthrough also validated efforts by Asst Prof Loo and Asst Prof Ng to pioneer a research group in the emerging field of nanotoxicology, which is still very much in its infancy throughout the world.

Nanotoxicology studies materials to see if they are toxic or harmful when they are turned into nano-sized particles. This is because nanomaterials usually have very different properties when compared to when the materials are of a larger size.

Asst Prof Ng said the team will carry out further research as the DNA damage brought about by nano-sized Zinc Oxide particles is currently a result of an unknown mechanism. But what is clear is that besides causing DNA damage, nanoparticles can also cause other harmful effects when used in high doses.

“From our studies, we found that nanoparticles can also increase stress levels in cells, cause inflammation or simply kill cells,” said Asst Prof Ng who added that apart from finding out the cellular mechanism, more focused research is also expected to ascertain the physiological effects and damage that nano-sized Zinc Oxide particles can cause.

Asst Prof Loo pointed out that besides enhancing the understanding of the potential risks of using nanomaterials, advancements in nanotoxicology research will also help scientists put nanomaterials to good use in biomedical applications.

For example, although killing cells in our bodies is typically undesirable, this becomes a positive outcome if it can be effectively directed towards cancer cells in the body. At the same time, the team is also studying how nanomaterials can be “re-designed” to pose a lesser risk to humans, yet still possess the desired beneficial properties.

This research discovery is one of the latest in a series of biomedical breakthroughs by NTU in healthcare. Future healthcare is one of NTU’s Five Peaks of Excellence with which the university aims to make its mark globally under the NTU 2015 five-year strategic plan. The other four peaks are sustainable earth, new media, the best of the East and West, and innovation.

Moving forward, the team hopes to work with existing and new collaborative partners, within and outside of Singapore, to orchestrate a more concerted effort towards the advancement of the fledgling field of nanotoxicology here, with the aim of helping regulatory bodies in Singapore formulate guidelines to protect consumer interests.

The research team would also like to work with the European Union to uncover the risks involving nanomaterials and how these materials should be regulated before they are made commercially available. Asst Prof Joachim Loo, who received his Bachelor and Doctorate degrees from NTU, was the only Singaporean representative in a recent nanotechnology workshop held in Europe. At the workshop, it was agreed that research collaborations in nanotoxicology between EU and South-east Asia should be