Image: istockphoto

Like clockwork, brain regions in many songbird species expand and shrink seasonally in response to hormones.

Now, for the first time, University of Washington neurobiologists have interrupted this natural “annual remodeling” of the brain and have shown that there is a direct link between the death of old neurons and their replacement by newly born ones in a living vertebrate.

The scientists introduced a chemical into one side of sparrow brains in an area that helps control singing behavior to halt apoptosis, a cell suicide program. Twenty days after introduction of the hormones the researchers found that there were 48 percent fewer new neurons than there were in the side of the brain that did not receive the cell suicide inhibitor.

“This is the first demonstration that if you decrease apoptosis you also decrease the number of new brain cells in a live animal. The next step is to understand this process at the molecular level,” said Eliot Brenowitz, a UW professor of psychology and biology and co-author of a new study.

His co-author is Christopher Thompson, who earned his doctorate at the UW and is now at the Free University of Berlin. “The seasonal hormonal drop in birds may mimic what is an age-related drop in human hormone levels. Here we have a bird model that is natural and maybe similar genes have a similar function in humans with degenerative diseases such as Alzheimer’s and Parkinson’s, as well as strokes, which are associated with neuron death.”

The research involved Gambel’s white-crowned sparrows, a songbird subspecies that winters in California and migrates to Alaska in the spring and summer to breed and raise its young. The sparrow’s brain regions, including one called the HVC, which control learned song behavior in males, expand and shrink seasonally.

Read more on this study here

 The paper was published in a recent issue of the Journal of Neuroscience.

Source: EurekAlert

WE ALL MAKE mistakes, but now researchers have found a way to predict when you are about to make one – a full 20 seconds ahead of time.

The discovery at Trinity College Dublin’s School of Psychology and Institute of Neuroscience immediately offers the possibility of developing an early warning system that can watch for lapses in attention, say in long distance truck drivers. The finding may also point to new highly sensitive methods for detecting the onset of neurological problems such as Alzheimer’s disease, suggests lead researcher and professor of psychology Ian Robertson.

He and Dr Redmond O’Connell collaborated with a group from the Nathan S Kline Institute for Psychiatric Research in New York in a study published last month in the Journal of Neuroscience.

The research sought to examine in very precise detail processes in the brain related to our ability to pay attention. “Attention with memory is one of the most important human faculties,” Robertson suggests.

It is disrupted in conditions such as dementia, attention disorders and with emotional disturbances and so lies at the heart of these conditions. He describes attention as “the ability to select certain information relevant to everyday activities”; in effect, keeping focused on what is important and ignoring distractions.

“An awful lot of accidents are caused by people not selecting the right information or not focusing on the right things,” says Robertson.

Being able to maintain focus is an essential part of modern living, but doing so in the face of a tedious task, such as long-haul driving or flying an aircraft, runs counter to the way our brains are programmed to work.

“The human brain is an organ that loves variety, that likes new things,” Robertson says.

Researchers began looking at attention more closely after the introduction of radar. Operators found it difficult to maintain their focus on a screen that seldom changed, leading to an increased risk of errors. “This research was an attempt to explore exactly what happens in the brain when attention wanders,” he explains.

Redmond O’Connell was first author on the project, which involved getting 21 subjects to undergo a screen-based test of concentration while monitoring their background brain activity using an electroencephalogram. The EEG uses electrodes placed on the scalp to detect tiny electrical signals given off by the brain while active and at rest.

This provided two streams of information that were synchronised, one the EEG read-out and another which tracked the person’s interaction with the computer screen.

The test was very simple, but demanded constant attention to avoid errors, O’Connell says. Subjects watched changing checkerboard patterns and were asked to push a button when they saw a pattern that remained on the screen slightly longer than the others. The patterns were not important, it was the time they stayed on the screen, he says.

Subjects took a series of 10 three-minute tests. “When you do the task you really do feel like you have been a boxing ring,” he says.

Once completed, the test results were averaged and then compared to what the EEG was showing. The team was startled to see that the EEG, when recording a brain signal based on production of something called alpha waves, could show in advance when the subject was losing focus and about to make a mistake.

“Our results show that the specific neural signatures of attentional lapses are registered in the EEG up to 20 seconds before an error,” the authors write in their research paper.

This has immediate implications for accident avoidance and safety, O’Connell believes. “This tells us it is possible to predict a loss of attention.” It should be feasible to develop a device that could monitor for this and emit a warning signal.

“It might also provide a more accurate marker for gradual neurological decline,” Robertson adds. “It would provide a very sensitive marker for a very important brain function.” It might give a much earlier warning of advancing dementia long before symptoms begin to arise.

© 2009 The Irish Times

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Botox of course already had a history as a treatment for medical conditions like  excessive sweating before it became the commonplace cosmetic procedure we know it best as today.

Scientists believe emotions can be “reverse engineered” — if a patient is prevented from frowning, the theory goes, their brain may think there is nothing to worry about.

“The basic principle is that there is feedback from the body to the brain so the brain always knows what the body is doing,” said Marc Axel Wollmer, the psychiatrist in charge of the trials being held jointly at Basle University, Switzerland, and Hanover University, Germany.

“If we have an emotion like joy or grief we also have a facial expression that corresponds,” he said. “Studies indicate that if we deliberately produce a facial expression, there is a change in feeling.”

The theory is called “facial feedback hypothesis”. Another example is that someone who is forced to smile at a social event where the person is feeling uncomfortable may find he or she enjoys it more.

An initial experiment by another team used Botox on 10 depressed patients. After two months nine were no longer depressed and the 10th patient reported an improvement in mood.

“We are not interested in treating people unhappy with the cosmetic appearance of their lines,” said Wollmer. “They will feel happier after treatment because they like their looks better. That would be too simple.”

(Source: Sunday Times 2/9/09)

On 8 March 1969, an extraordinary experiment was reported in the pages of Nature, Europe’s leading science journal. It involved a group of people who took turns to sit in an old dentist’s chair and describe the room around them. They commented on the presence of a phone on the table, a nearby vase, people’s expressions and how they wore their hair. It was remarkable because all were completely blind.

The scientific establishment took a dim view of the work and, for the most part, dismissed it as implausible. But today it stands as one of the first, and most striking, demonstrations of neuroplasticity, the brain’s ability to adapt. The blind people had learned to “see” through the sensation of touch.

Here’s what happened. The back of the chair had been fitted with hundreds of tiny stimulators that were hooked up to a video camera. As the camera panned the room, those in the chair felt tiny vibrations that seemed to dance across their skin as the image moved. With practice, the blind volunteers’ brains learned to turn these vibrations into a mental picture of the room. Some became so good at it that they ducked when a ball was tossed at the camera.

What was regarded as fringe science 40 years ago is currently at the cutting edge of  neurscience. . With the right training, scientists now know the brain can reshape itself to work around dead and damaged areas, often with dramatic benefits. Therapies that exploit the brain’s power to adapt have helped people overcome damage caused by strokes, depression, anxiety and learning disabilities, and may one day replace drugs for some of these conditions. Some studies suggest therapies that tap into the brain’s neuroplasticity are already making a big difference. Children with language difficulties have been shown to make significant progress using computer training tools that are the equivalent of cerebral cross-training. Work is underway to investigate whether it is possible to stave off a loss of brain plasticity in older age, which might help to address memory problems linked to Alzheimer’s disease. Some psychoanalysts are adopting techniques to help people overcome relationship troubles, obsessions, worries and bad habits.

The idea of brain plasticity has been discovered and forgotten many times over the centuries. The ancient Greeks accepted the idea, with Socrates believing that people could train their brains the way gymnasts train their bodies. Around the time of Galileo, the idea fell out of favour, as scientists began to see the world mechanistically, with each object, organ and even parts of an organ being attributed well-defined, unchanging roles. It was these ideas that led to the notion of our brains being “hardwired”, an idea that today is steadily being overturned.

Norman Doidge, a psychiatrist at the University of Toronto and author of the New York Times bestseller, The Brain That Changes Itself, says our ongoing belief that our brains are hardwired has held up medical progress. “Our best and brightest neuroscientists thought our brains were structured like complex machines, with each part performing one function in one location, and that had implications. If you were born with a part that was defective, and say it gave you a learning disorder, it meant there was nothing you could do, you had to learn to live with it. If you sustained a brain injury or had a stroke and part of your brain broke down, there was nothing you could do. Brain exercises made no sense, and even more fundamentally, human nature was as fixed as the brain from which it emerged,” he says.

Neuroplasticity does not see the different regions of the brain as completely versatile and certainly not interchangeable. But it recognises that if part of the brain is damaged, it can be possible to train other areas to take on, at least to some extent, the job of the lost brain matter.

One of Doidge’s case studies, Cheryl Schiltz, demonstrates how brain plasticity can transform a damaged life. Her story began in 1997, when, at the age of 39, she picked up an infection after a routine operation. To clear it up, she was given a course of the antibiotic, gentamicin. When used in excess, the drug can sometimes destroy cells in the inner ear, causing hearing loss, but it is cheap and effective, so is widely used. In Schiltz’s case, gentamicin destroyed her vestibulary system, the looping canals of the inner ear that allow us to tell up from down. Tests showed she had only 2% of her vestibulary function left.

What happens to a person who cannot balance is striking. Schiltz felt as if she was constantly falling, and as a result, she usually did. When she hit the floor, the feeling didn’t go away. Sometimes, it was as if a trapdoor had opened and she was free-falling into an abyss.

Her doctor found an ingenious way to treat her. He fitted her with a bizarre-looking helmet fitted with motion sensors. These fed signals to a metal strip that she placed in her mouth. Now, as she tipped forward, she felt a tingle ripple to the tip of her tongue. As her head moved to the side, the tingle rolled sideways.

The first time Schiltz put the device on she began to cry. The wobbles subsided. She felt safe. She could stand up. Over time, her brain learned to turn the feeling in her tongue into a sense of balance. After prolonged training sessions, Schiltz needed the helmet less and less. Her doctor thinks her brain tuned into the tiny signals coming from what remained of her vestibulary system, and recruited other brain nerves to help out.

There is a darker side to brain plasticity that Doidge has seen in some of his own patients. He has treated several men whose relationships were in tatters because of what Doidge calls an “epidemic” of internet porn addiction. The men had spent so much time viewing pornographic images, they had become impotent with their partners, and some developed extreme sexual tastes. Doidge believes that neuroplasticity was at work here, with the men’s brains altered by an almost limitless supply of pictures, available any time at the click of a mouse. Most of the men recovered after being banned from using their computers and going cold turkey.

Some psychiatrists suspect that a common technique called cognitive behaviour therapy, which helps people to change their perspective on events in their lives, may work because of the brain’s plasticity.

In his book, Doidge uses ideas of neuro-plasticity to promote ways of overcoming conditions such as obsessive-compulsive disorder, and other common problems, such as persistent worries and anxieties. In some instances, he suggests that people force themselves to do a rewarding task as soon as they get the urge to worry or check whether the stove is off for the seventh time. “You have a real civil war for four to six weeks, because your brain is pulling you one way and you are pushing in another, but when it works, it is very powerful,” he says.

Doidge says he is not anti-medication, but wonders if therapies that tap into neuro-plasticity will soon replace drug treatments for certain conditions. “We can change our brains by sensing, imagining and acting in the world. It’s economical and mostly low-tech, and I’m very, very hopeful”.

The Brain That Changes Itself by Norman Doidge is published by Penguin.

Source: Guardian online

New research gives a possible explanation for why some of us are thrill seekers and others like to play it safe. The study found that some of us can’t control the release of a certain brain chemical.

Wouldn’t it be amazing if researchers could scan our brains and see whether we have thrill seeking personality traits? Vanderbilt University psychologist David Zald  has come pretty close. He has conducted a study that links thrill seeking behavior with a difference in specific part of the dopamine system in the brain.

“Dopamine does a number of different things. Probably most importantly though it’s involved in motivation and reward,” explains Zald. “And it’s the critical chemical in terms of people really wanting to do things.”

Specific brain cells, or neurons, make and release dopamine. When dopamine is released its target is specific dopamine receptors on other brain cells in the pleasure centers of the brain. There have been some studies of these receptors in people. But Zald wanted to look at a different structure on the dopamine releasing brain cells themselves, called autoreceptors, which function as brakes to stop the release of dopamine.

Zald knew that studies in rodents showed that those with reduced brakes were more likely to explore in novel environments but were also more likely to self-administer cocaine or amphetamines. He also knew there was some limited evidence that individual differences in dopamine functioning was linked to novelty seeking.

He and his colleagues asked 34 healthy male and female volunteers to fill out a questionnaire that measures a person’s tendency for novelty seeking.

“The scale that we used measured things like how much the person wants to try new things, how free they are in terms of spending money, and the person’s willingness to be spontaneous or even break rules,” Zald explains.

Then his team scanned the brains of the volunteers using  PET scanners.  They measured the number of autoreceptors, the structures that act like brakes on dopamine release. As they wrote in the Journal of Neuroscience,  low thrill seekers had many brakes while high thrill seekers had very few. In the brain scans in the image above comparing a low and high thrill seeker, the white arrows point to the autoreceptors, which show up as bright blue.

“What we think that means is people who really don’t have the brakes on their dopamine system, they’re really going to release more dopamine and have more of the rewarding effects of dopamine,” says Zald.

Zald says that there are positive and negative aspects to the novelty seeking personality trait.

“Thrill seeking is one of the things that leads people to explore new things, to discover new things,” says Zald. “The world would be a boring place if we didn’t have people who were willing to take the risks because they were so interested or drawn to the new and exciting.”

But people with the novelty seeking trait are also at a higher risk of doing drugs. Zald wants to do further studies to find out why some people take such deadly risks and others find ways to balance their need for excitement in healthier ways.

And Zald has a word of advice for parents: “For a child who is a thrill seeker, what you really want to do is direct them into activities which will give them those thrills. For instance having them learn to do rock climbing would be a good example. And if they can get those thrills through something where they maintain a reasonable level of safety, that may be a draw that is enough for them so they never feel the need or desire to start experimenting with drugs.”

Publication: Journal of Neuroscience
Authors: David H. Zald, Ronald L. Cowan, Patrizia Riccardi, Ronald M. Baldwin, M. Sib Ansari, Rui Li, Evan S. Shelby, Clarence E. Smith, Maureen McHugo, and Robert M. Kessler
Research funded by: National Institute of Drug Abuse

Source: ScienCentral

People with bad eating habits have “devilish” brains that prevent them exercising self-control.

Researchers in the US discovered an “angel” centre in the brain that holds back a “devil” region to stop us giving in to temptation. It allows people to weigh abstract considerations such as “healthiness” against basic desires – for instance, a craving for tasty, rich food.

However, scientists found that the effect is strong in individuals with good self control but less pronounced in the weak-willed. Dr Antonio Rangel, from the California Institute of Technology, whose research appears in the journal Science, said: “A very basic question in economics, psychology, and even religion, is why some people can exercise self-control but others cannot. From the perspective of modern neuroscience, the question becomes, “what is special about the circuitry of brains that can exercise good behavioural self-control?’ This paper studies this question in the context of dieting decisions and provides an important insight.”

Dr Rangel’s team showed a group of dieting volunteers photos of 50 foods ranging from chocolate bars to cauliflower.
Participants were asked to rate each food according to its taste and healthiness.
A “reference” food was then picked for each person which he or she regarded as neutral with respect to taste and health. They were then asked to choose between their reference foods and other dishes, while their brain activity was scanned.

A pattern emerged as participants with strong self control signals were able to balance health and taste and opt for healthier foods. Those whose “angels” did not speak loudly enough chose the tastier foods, regardless of nutritional value. “After centuries of debate in social sciences we are finally making big strides in understanding self-control from watching the brain resist temptation directly,” said co-author Prof Colin Camerer. “This study, and many more to come, will eventually lead to much better theories about how self-control develops and how it works for different kinds of temptations.”

The “angel” centre’s technical name is the dorsolateral prefrontal cortex (DLPFC). Researchers hope to find ways to engage this in people with poor self control – for instance, it might be possible to kick it into gear by making the health qualities of foods more obvious, they said.

 This story appeared in the printed version of the Irish Examiner.

Skin provides the first level of defense to infection, serving not only as a physical barrier, but also as a site for white blood cells to attack invading bacteria and viruses. The immune cells in skin can over-react, however, resulting in inflammatory skin diseases such as atopic dermatitis and psoriasis.

Stress can trigger an outbreak in patients suffering from inflammatory skin conditions. This cross talk between stress perception, which involves the brain, and the skin is mediated the through the “brain-skin connection”. Yet, little is know about the means by which stress aggravates skin diseases.

Read more here

Never mind sugar and spice and puppy dogs’ tails; this is what divides the boys from the girls. A study based on the brain scans of youngsters has shown why girls prefer a best friend while boys gravitate towards packs. The research found that girls are hardwired to understand individual relationships, while boys’ brains are more attuned to the complex dynamics and internal competition within a gang. The study, conducted by researchers at the National Institute of Mental Health in the United States, gauged the effects of a process familiar to many households: children becoming more interested in interacting with their peers as they grow older. The study used magnetic resonance imaging scanners to monitor the brains of 34 young people, aged nine to 17, as they were shown pictures of new people they could choose to meet. The tests showed that the circuitry in the brain responsible for sizing people up became more active in girls as their age increased, but not in boys. Daniel Pine, the child psychiatrist who led the study, says the social differences between girls and boys intensify around adolescence. “One-on-one individual relationships tend to become very important for girls around adolescence, while aspects of relationships that manifest in competitions, such as in sporting events, become very common among boys,” he said. The scans suggest that as girls progress from childhood to adolescence, certain areas of their brain become increasingly stimulated when they are faced with a one-to-one social encounter. If the girl is interested in the person, her hypothalamus (associated with hormone secretion), hippocampus (linked to learning), insula (which affects feelings) and nucleus accumbens (motivation and reward) are all activated. Boys, by contrast, show a slight decline in activity in these areas, indicating they are less stimulated by personal interactions than girls are. “Complex behaviours such as how girls perceive social clues are shaped both by things that are intrinsic to people — part of who they are — but also by things out in the environment,” Pine said. In addition, the research has provided clues as to why teenage girls are more prone to anxiety and depression. The parts of the brain that showed increased activity in social situations are also those related to depression. Source: Times