Hyperbaric chamber may treat traumatic brain injury

The Defense Department hopes to find a better treatment for the 100,000 troops who have been diagnosed with mild traumatic brain injury since 2003, and it's looking at hyperbaric chambers — often used in cases of carbon monoxide poisoning — for the answer.

Although there have been studies looking at the impact these pressurized oxygen chambers have on TBI patients, none has been able to definitively answer whether hyperbaric oxygen can reduce or eliminate chronic symptoms of TBI such as headaches, memory loss and mood swings. A new clinical trial, which is expected to begin in January 2011, is designed to do just that.

The study, conducted by the Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury in Virginia, and the Army Research and Materiel Command in Maryland, is expected to run for at least 18 months. It will include about 300 participants, mostly soldiers and Marines, and will build upon other ongoing studies on TBI treatment, said Col. Richard Ricciardi, director of the research evaluation and quality assurance and surveillance directorate at Defense Centers of Excellence.

TREATMENT: Pentagon focuses on traumatic brain injury

Five sites will participate in the study: Fort Carson, Colo.; Camp Pendleton, Calif.; Camp Lejeune, N.C.; Brooks City-Base, Texas; and possibly Fort Hood, Texas, although negotiations are still ongoing there, Ricciardi said.

Individuals getting the experimental treatment will breathe 100% oxygen while inside the hyperbaric chamber at 1.35 atmospheres of pressure — about the same amount of pressure you would feel if you dived 20 to 25 feet below water. The theory is that the pressure created by the chamber causes oxygen in the blood to dissolve, allowing more oxygen to flow through the body and repair damaged tissue.

A control group will feel a similar amount of pressure inside the chamber, but will breathe regular air, which will dissolve at the regular rate, he said.

The chambers will hold three to 16 participants. Each person will be asked to sit in the chamber for one hour a day, five days a week for 40 sessions. The study is primarily looking at service members who suffered a TBI about four to six months ago, and are going through the healing process, he said.

Soldiers interested in participating in the study should talk to their health care provider to see if there are clinical trials available in their area and whether they are a candidate for those trials.

Brain gets 'high' from junk food

The same brain pathways that make people addicted to drugs also addict them to high calorie foods, according to a recent US study.

The research adds credence to some scientists' belief that addiction to pleasure comes from over-stimulation, and that there may be a neurological way to treat overeating.

For the study, scientists fed high-calorie food such as bacon, sausages, and cheesecake to rats.

After the rats had gained a lot of weight from eating such high-fat food, scientists compared them to rats raised on a well-balanced diet.

The rats fed junk food ate twice as many calories, on average, as the second set of rats.

Paul Kenny, an associate professor at the Scripps Research Institute in Florida, said that when he and his colleagues removed junk food from the rats' diets, the rats refused to eat at all.

He said that they changed their diet preference so greatly that they basically starved themselves for two weeks after being forced to eat mainly vegetables and low-fat foods.

The researchers also used electric shock in order to prevent the rats from overeating.

However, the rats ignored the electric shocks and continued to eat.

After the researchers felt they had definitely established that the rats were addicted to pleasure, they attempted to find a neurological basis for the addiction itself.

Kenny and another student focused on the neurotransmitter dopamine, which is released during sex, eating, and drug use.

Other studies had shown that cocaine users have decreased levels of dopamine in their brains, after they have used the drug.

In cocaine users, once dopamine flooding has caused over-stimulation, the appropriate brain receptors require more cocaine than before in order to establish the same level of flooding as before.

People consequently become addicted to cocaine, because in order to establish the same level of flooding as before they must take it in increasingly larger amounts, and more and more often.

For the present study, the researchers found that the food-addicted mice had gone through the same kind of neurological transformation.

Kenny said that his team's findings confirmed what they and many others had always suspected, that the mechanism of addiction drove the development of compulsive eating.

The amazing brain

The news that scientists can switch off our morals with a magnet illustrates how much we still have to learn about our little grey cells, says Richard Gray.

Richard Gray at the University of Essex, wearing a cap with electrodes attached which measure electrical impulses in the brain Photo: Oli Scarff

I once moved an object with the power of my brain. Admittedly, the object in question was a small white bar on a computer screen, and the effort of moving it just a few faltering inches to the left turned me purple with concentration. I also needed to wear a daft-looking skullcap, which had me bristling with wires like a futuristic Medusa. But it is still amazing to recall that, just by thinking at it, I was able to control a computer.
Most of us tend not to contemplate the stuff sitting between our ears. But each of us is carrying around one of the most amazing objects ever created – and one that governs almost everything about how and why we think, feel, act and believe.
For example, we think of our ability to distinguish between right and wrong as a fundamental part of what makes us human, giving us a grasp of morality and philosophy. But yesterday, researchers revealed in Proceedings of the National Academy of Sciences that they had essentially been able to switch off their subjects' moral compasses, by applying powerful magnets to a small region of the brain just behind the right ear.
Volunteers subjected to magnetic pulses to the right temporo-parietal junction, an area that is highly active when we think about the thoughts and beliefs of others, were more likely to make morally dubious decisions. For example, they were asked whether it was right to have let your girlfriend walk across a bridge you knew was unsafe. Because she made it across, the decision was seen as correct; the ends had justified the means.
Such experiments are helping us to realise the extent to which the brain is, in the words of Professor Colin Blakemore, a leading neuroscientist at Oxford University, "the machine that runs our lives". "It is responsible for everything we do," he says, "every belief, intention and action. Physically, all we can do is move our muscles, but to do this we need nerve impulses from the brain. In the same way, moral and ethical choices are just functions of the brain, just as picking up a cup of tea and drinking it is."
In fact, every movement we make and breath we take is determined, subconsciously, by our brains. As a result, it is a greedy organ. The brain makes up just 2 per cent of a person's body weight, but uses around 25 per cent of the oxygen we inhale and consumes 20 per cent of the body's energy. It is the size and immense adaptability of the human brain that is responsible for the transformation of our species from tree-dwelling primates into the dominant species on the planet.
Our brain size was achieved due, scientists now believe, to the demands of social networking (in other apes, it has been observed that the larger the group size, the larger a part of the brain known as the neocortex becomes. It is thought that the human brain grew so large, and our species became so clever, as our social groups expanded).
In its most basic form, the brain is a cluster of nerve cells, capable of communicating with each other using tiny pulses of electricity. Interfere with this communication, as the researchers from MIT did, and strange things start to happen. One often cited example is a rare medical condition known as foreign accent syndrome, of which there have been just 60 recorded cases in the past 70 years. Researchers at Oxford University found that people who have suffered an injury to key parts of their brain underwent a strange transformation. In one case, a stroke victim from Newcastle switched from speaking with a broad Geordie accent to a Jamaican, and occasionally Slovak, tone.
The reason this can happen is that our memories, personalities and behaviour are not innate parts of our genetic make-up but learned information, stored up in those little nerve cells. "The brain is extremely fragile," says Prof Blakemore. "Unlike other parts of our body, like the heart or our muscles, much of the information it holds is not contained within our genes."
If we lose the networks of cells that hold this information, dramatic changes can occur. Using a technique known as Transcranial Magnetic Stimulation, researchers can temporarily switch off parts of the brain. In a paper due to be published later this week in Journal of Cognitive Neuroscience, Dr Joe Devlin of University College London has shown that it is possible to slow volunteers' reading ability by directing magnetic pulses to a part of their brain known as the ventral occipito-temporal cortex.
For an example of this type of brain surgery with a permanent effect, we can look to the case of Phineas Gage, a 19th-century railway worker. Gage was injured in an accident in which a rod passed though his skull and destroyed a large part of his brain. He miraculously survived and was mentally unimpaired, with one exception: his personality. Before the accident, he was hard-working and good-natured, but he became ill-tempered and generally disliked. The rod had damaged a significant part of his frontal lobe, a part of the brain now known to be essential in governing our temperament.
The fact that nerve cells can lose the information they capture is one of their greatest weaknesses – but their response to such accidents showcases one of their greatest strengths. When we have a stroke, our brain is starved of oxygen, causing the catastrophic death of those nerve cells and leaving us paralysed and unable to speak. Yet within days, the same patients start to regain movement and the ability to speak. This is not a sign of nerves coming back to life, but the brain rebuilding itself, creating new nerve connections and bypassing the damaged areas.
"It is extremely useful to have a brain that can remodel and rewire itself," says Professor Blakemore. "The ability of the brain to absorb information, form new memories and learn new skills is all dependent on genetic mechanisms in nerve cells. These enable the cells to change their form, shape, size, connections and therefore their function. They are self-learning devices."
Professor Blakemore believes this property, known as "plasticity", can be exploited to our benefit. Working with researchers in Düsseldorf, he is developing a system that has enabled blind patients to see using sound. He has found that their brains remodel to use variations in pitch, tone and volume – in the same way sighted people use differences in light and colour – to build up a picture of their surroundings. Over several weeks of training, patients became able to recognise different objects using the sounds.
It appears, however, that this process is not just limited to those who have suffered an injury. Dr Heidi Johansen-Berg, from the University of Oxford, recently discovered that practising juggling could lead to changes in the white matter of the brain, enhancing the number of connections between nerves. Her findings have helped to transform conventional ideas about how the brain starts to deteriorate once we reach our teenage years.
"We tend to think of the brain as being static or even beginning to degenerate once we reach adulthood," she says. "We've shown that it is possible for the brain to condition its own wiring system to operate more efficiently." Indeed, scientists are discovering that the brain can be influenced by large numbers of stimuli: computer games such as Tetris have also been found to increase the amount of brain matter.
It is clear, then, that science is only just starting to scratch the surface of what the brain is capable of, and how exactly it makes us who we are. "I suspect that human potential is nowhere near its limits," says Prof Blakemore. "As we accumulate more knowledge, we will change our brains in doing so and so go on to generate yet more knowledge. There might be no limits to what the human brain can achieve."
Parts of the brain
Cerebellum
Co-ordinates movement, balance and reflex reactions. Injury to this part of the brain leads to dizziness and loss of the ability to walk and to control fine movements.
Primary Motor Cortex
Responsible for initiating voluntary movement.
Temporal Lobe
Responsible for hearing, memory formation and recognition of objects. Injuries can lead to short-term memory loss and aggression, and leave victims unable to recognise faces.
Occipital Lobes
These contain the visual cortex, responsible for processing information from the eyes. Recently found to play a major role in reading and writing.
Frontal Lobe
Responsible for consciousness, and governs habits, motor skills and personality traits. Injury can lead to paralysis, mood changes and the inability to plan actions such as making a cup of tea.
Parietal Lobe
Combines sensory information to form a single concept.
Limbic System
The more primal part of the brain, responsible for emotions, sexual arousal, rage and fear. Also controls the biological rhythms of the body.

Think again: reinterpreting the brain

THE old textbook diagram of the human brain with dotted lines and labels like ''speech'' or ''vision'' is becoming obsolete.
The US psychiatrist Norman Doidge's book The Brain That Changes Itself portrays the brain more like the grand staircase at Hogwarts School of Wizardry, neurons constantly shifting, reconnecting and disconnecting. Each new connection is part of a skill, memory or feeling we can learn or unlearn.
Doidge argues that psychiatric treatment could encourage new ''mind maps'' - areas of neural activity we can engineer to cure everything from phantom limb syndrome to addiction.
Perminder Sachdev, professor of neuropsychiatry at the University of NSW and author of The Yipping Tiger and Other Tales from the Neuropsychiatric Clinic, agrees with the principle of neuroplasticity, but reminds us the brain is not nearly that simple.
"Notions about the rigidity of the brain have been challenged in the last 20 years," he says. "After a stroke there is a lot of dysfunction but it gradually improves … Some of that recovery is because some neurons recover, so we've realised there is some plasticity in the network.
''But after a very dense stroke people are often left with a severe deficit that's difficult to manipulate with physiotherapy or other techniques, so there's a constraint on how plastic the brain will be."
Many of the treatments mentioned in Doidge's book involve simple repetition, actions that generate neural networks to create a new reality. Tie two fingers together for a month, he says, and when you untie them you won't be able to move one without the other. The mind map covering their use has been rewired to consider them co-dependent.
Revelations about our feelings, memories or abilities is emerging across neuroscience. If you believe in an immutable sense of self - your ''soul'' - you might be disturbed by research from Rebecca Saxe, associate professor of cognitive neuroscience at MIT. She applied a magnetic field to a brain region associated with moral judgment and changed the way subjects reacted to hypothetical moral scenarios. The manipulation of neurons had literally changed people's ethics.
If we can indeed rewire ourselves to break a habit, make a task second nature, or alter aspects of our essential selves - such as our morals - maybe there's no ''self'' at all, just microscopic electrical networks reacting to the environment.
Together with neuroplasticity, research has revealed a new model of mental cohesion. We are all familiar with the sensation of being at war with ourselves - reason fighting with emotion and left-brain functions struggling against those of the right.
Culturally, we tend to distrust emotion but maintain anything that is culturally important according to reason. Our entire judicial system is based on the dispassionate attention to facts. Star Trek's Mr Spock was seen as the pinnacle humanity should hope for, committed to impartial logic instead of being a slave to passions like the human crew.
The US science author Jonah Lehrer offers a new way to look at this in his book The Decisive Moment. Instead of jostling to portray their exclusive version of the world around us, separate functions of the mind like reason and emotion work beautifully together.
Being at work all day when it's beautiful outside is not fun, but we do it because we know our bills need to be paid - that's the ''big picture'' appreciation of reason at work. Emotion gives us a short, reactive flash of tightly focused insight, and when it really matters - such as when faced with a predator - it gives us the power of rapid response where applying objective reason to every aspect of the environment would take too long and cripple us with indecisiveness.
But there is a dark side. Sometimes the tightly focused insight can lead us astray from the big picture without us knowing.
As the Washington Post science writer Shankar Vedantam says in his book The Hidden Brain, emotional response is one of ''speed at the expense of sophistication''. Unconscious filters about a situation or person go to work immediately, and the distorted vision that sometimes results is responsible for a host of social ills. In one experiment schoolchildren who were asked to judge photographs of faces overwhelmingly chose those of black-skinned people as ''evil''.
''All of us have our biases or prejudices,'' says Sachdev. ''We've learnt them from exposure to cultural artefacts over a period of time. It's possible to change with education and repeated counter-exposure, although it's difficult to say whether they can be completely eliminated … But the strength of these connections can be weakened.''
And whatever advanced neurological treatments we can subject ourselves to, Sachdev explains the beautiful elegance of the neural mapping we do every day. ''We can change our minds.''

Disruption in Brain Connection Linked to Genetic Defect in Schizophrenia

In what may provide the most compelling evidence to date, researchers at Columbia University Medical Center have illuminated how a genetic variant may lead to schizophrenia by causing a disruption in communication between the hippocampus and prefrontal cortex regions of the brain, areas believed to be responsible for carrying out working memory. Findings are published in the current online edition of Nature.
This discovery coincides with the 15th anniversary of the first identification of the link between schizophrenia and a genetic mutation -- a microdeletion on human chromosome 22 -- known as 22q11 deletion, by Columbia Psychiatry researcher Maria Karayiorgou, M.D., a coauthor on the research. Previous studies have shown that approximately 30 percent of patients with this deletion will go on to develop schizophrenia.
"We know that this genetic deficit predisposes us to schizophrenia, and now we have identified a clear pathophysiological mechanism of how this deletion confers this risk for schizophrenia," said Dr. Karayiorgou. Dr. Karayiorgou discovered the link between the 22q11 mutation and schizophrenia in 1995. Since then, Dr. Karayiorgou and Joseph A. Gogos, M.D., Ph.D, a senior author on the research, have established and pursued research focusing on the neurobiology of this mutation.
Though schizophrenia is best known for its delusions and hallucinations, it is the disease's impact on such cognitive abilities like working memory -- a key element of executive functioning -- that best predict how well a person will function in society.
Using a mouse model with the 22q11 deletion, senior authors Joshua Gordon, M.D., Ph.D., and Joseph A. Gogos, M.D., Ph.D., and their teams, recorded the neural activity of the mice while they performed a cognitive task of working memory, and found that their performance was either completely disrupted, or was impaired, compared to that of the healthy mice.
(Dr. Karayiorgou is professor of psychiatry, Dr. Gogos is associate professor of physiology and neuroscience, and Dr. Gordon is assistant professor of psychiatry at Columbia University Medical Center).
In healthy mice, the hippocampus sends spatial information to the prefrontal cortex, but in the mouse model of the 22q11 mutation there is a breakdown in the connection and this communication is either weakened or fails completely.
As part of the cognitive trial, the mice were tested as they navigated a t-shaped maze. In order to successfully complete the task, the mice had to recall the direction in which they traveled, and then choose to go in the opposite direction to receive their next reward. While the healthy mice easily learned the task, mice carrying the schizophrenia mutation took longer to master it, demonstrating a behavioral deficit of the task in the mouse model of schizophrenia.
"We found that successful completion of the task in our healthy mice required the two regions of the brain -- the hippocampus and the prefrontal cortex -- to work together, and in our mouse model, the information transfer was less efficient, or was unable to take place at all," said Dr. Gordon.
In addition, the researchers reported that they were able to show the extent of the deficit in individual mice.
"There was a variation in how much of a deficit they showed, and that correlated with the degree of the behavioral deficit, so that for individual mice that have less communication between these structures, there was more of a behavioral deficit," said Torfi Sigurdsson, Ph.D., a postdoctoral research scientist in Dr. Gordon's laboratory at Columbia Psychiatry and a coauthor on the paper.
Recent human imaging studies have suggested the possibility that there may be abnormalities in the functional connectivity between the hippocampus and prefrontal cortex in schizophrenia, however, it remained unclear how such findings related to a cause of the disease, like that of a genetic risk variant, or if they were the result of the disease itself or medications used.
"Here we are really at the level of the individual cells, so our findings extend beyond patient studies by showing how disrupted connectivity can arise at the level of single neurons, as a result of a genetic risk variant," said Dr. Sigurdsson.
Another strength of the study, according to the researchers, is that the communication can be measured directly between the two regions.
"It unequivocally establishes a deficit in that communication in a way that the early studies could not -- not only because we can isolate the genetics of the disease, but we can also measure the connectivity between these structures directly," said Dr. Gordon.
"The 22q11 deletion mouse model allows us to explore how these mutations alter brain function and the abnormal behavior that we see in schizophrenia patients. This is exactly what our study and our research program on 22q11, in general, has accomplished," said Dr. Gogos.
"We now know that one of the consequences of that deletion is to disrupt functional communication between these two brain regions, and we have evidence from the study that the disruption actually has an impact on a cognitive behavior that is disrupted in patients, so it gives us a really strong indication of how the deletion can contribute to the development of schizophrenia," he added. "It is possible that similar abnormalities in functional connectivity may also account for other symptoms of the disease, and can be used to better assess treatment response, and, most importantly, to develop new medications."
Next, the researchers plan to test the structural links between the hippocampus and prefrontal cortex, since it appears likely that synchrony between these two regions is mediated through anatomical connections. The researchers will examine how the anatomical and synaptic properties of these connections change in this mouse model and will aim to identify the genes that account for this change.
Authors of the Nature study are Torfi Sigurdsson, Kimberly L. Stark, Maria Karayiorgou, Joseph A. Gogos and Joshua A. Gordon.
This study was supported in part by the Simons Foundation, the National Institute of Mental Health (NIMH), and the Lieber Center of Schizophrenia Research and Treatment.
Contrary to popular belief, schizophrenia is not a split personality; it is a chronic, severe, and disabling brain disorder that affects just over one percent of the adult population and is characterized by loss of contact with reality (psychosis), hallucinations (usually, hearing voices), firmly held false beliefs (delusions), abnormal thinking, a restricted range of emotions (flattened affect) or inappropriate and disorganized behavior, social withdrawal, and diminished motivation.
The disease often strikes in the early adult years, and although many individuals experience some recovery, many others experience substantial and lifelong disability. People with schizophrenia often have problems functioning in society and in relationships and are over-represented on disability rolls and among the homeless and imprisoned.
What precisely causes schizophrenia is not known, but current research suggests a combination of hereditary and environmental factors. Fundamentally, however, it is a biologic problem (involving changes in the brain), not one caused by poor parenting or a mentally unhealthy environment.

Blood Gives Clues to ‘Executive Thinking’ Problems

High blood levels of C-reactive protein (CRP) are associated with problems in executive thinking skills, such as planning, decision-making and self-control, says a German study.
CRP is considered an indicator of inflammation.
For the study, 447 older people underwent brain scans and were given tests of verbal memory, word fluency and executive function. Overall, the average time to complete the test of executive function was 85 seconds. But participants with the highest levels of CRP took an average of seven seconds longer to complete the test than those with the lowest CRP levels.
The researchers also found that those with the highest CRP levels had brain changes equivalent to 12 more years of aging than those with the lowest CRP levels.
There was no link between CRP levels and other cognitive functions, such as memory and language.
The study is in the March 30 issue of Neurology.
“The use of aspirin and (cholesterol-lowering) statin drugs, as well as physical activity and controlling weight, can help lower CRP levels in the body, but our analyses did not consider whether therapy would be effective or not,” Dr. Heike Wersching of the University of Munster, an author of the study, said in a news release from the American Academy of Neurology.