Thursday, May 27, 2010

Research council funds study into ageing

THE Swindon-based Biotechnology and Biological Sciences Research Council is funding research to understand the effects of ageing on the brain.
A £5m grant has been awarded to scientists from the University of Cambridge and the MRC Cognition and Brain Sciences Unit, who aim to understand how brain ageing in healthy people affects abilities like language and memory.
The ageing process does not have a uniform effect across the brain. Older people often struggle to recall the right word in a conversation, but can continue to expand their vocabulary throughout old age.
Understanding what structures in the brain account for this variation will be a crucial first step allowing more people to retain a range of mental abilities throughout their lives.
Professor Lorraine Tyler of the University of Cambridge, who is leading the research, said: “Our mental abilities don’t suddenly start to decline as we enter retirement. In fact, many are retained right into our 80s and we are often too quick to attribute normal lapses like forgetfulness to the effects of age.
“Understanding the complexities of how ageing affects the brain will be crucial for older people to be able to live fulfilled lives and contribute fully to society. ”
The study is recruiting 3,000 people aged 18 to 88 years to create a large library of information on how healthy brain ageing affects mental abilities to different degrees.
Professor Douglas Kell, chief executive at the North Star-based BBSRC, said: “Improving the quality of life of ageing populations is a global research challenge, so it is vital that large studies like this provide data and resources for future scientists all over the world.”

Having Sex: It’s All in Your Head

Photo: Rankin
Photo: Rankin
So your kid wants to know how babies are made? Don’t hem and haw or spin some yarn about birds and bees—break down the biochemistry. It’s true what they say: The sexiest organ is the brain.
1/ Attraction
When a mommy and a daddy love each other very much, the neurons of the ventral tegmentum start producing the neurotransmitter dopamine and pumping it to the caudate nucleus, the hypothalamus, and other brain regions. High levels of dopamine can induce the release of testosterone, which is associated with a drive to make babies.

2/ Arousal
For daddies, physical and/or visual arousal can cause the neurotransmitter nitric oxide to be released by the autonomic nervous system. The chemical boosts the blood flow into the corpora cavernosa—the spongy tubes in the penis. As they inflate, the veins that would normally drain the blood are squeezed shut. Nitric oxide probably also causes clitoral swelling.
3/ Stimulation
Sexual stimulation triggers nerve cells in the brain to release stored oxytocin into the bloodstream. The hormone stimulates contractions in the smooth muscles of the uterus and of the male reproductive system, increasing enjoyment for both participants. In men, the theory goes, the contractions ultimately assist with ejaculation.
4/ Consummation
The climax phase of the sexual cycle triggers the release of more dopamine into the nucleus accumbens. (Known as the “reward area” of the brain, the accumbens is also associated with addiction.) Doing the deed also produces more testosterone. This can, in turn, result in a repetition of the act. Unless Mommy and Daddy have to get up early the next morning.

New Technique Fights Brain Tumors in Children

Proton Beam Therapy Gives Doctors New State-of-the-Art Tool in Combating Difficult Disease
    Addison Keegan, 2, who has undergone proton beam therapy for a brain tumor.
  • Brain tumors are the most difficult disease to treat in children, but now a new therapy for pediatric brain tumors is giving patients hope. Dr. Sanjay Gupta has more on this state-of-the-art treatment.
Addison Keegan, 2, who has undergone proton beam therapy for a brain tumor.  (CBS)


  • Addison Keegan is barely 2 -- and already a survivor. She had emergency surgery to remove a brain tumor four months ago. Now, her parents are trying a promising treatment in hopes her tumor doesn't grow back.

    "Just watching her and playing with her every day knowing we're doing what we can," said Kyle Keegan, Addison's father.

    Addison was healthy, developing normally, until violent flu symptoms lead to a devastating diagnosis in February: a brain tumor, called an Ependymoma, was lodged in her brain stem. Neurosurgeons removed as much as they could and luckily, it was benign.

    To kill residual tumor cells, instead of traditional radiation, Addison is undergoing "proton beam therapy," reports CNN Medical Correspondent Dr. Sanjay Gupta, a CBS News contributor.

    "This is going to be the standard of the future for pediatric brain tumors," said Dr. Robert Lustig, the director of radiation oncology at the University of Pennsylvania Hosptial.

    Normal radiation goes through the tumor into healthy tissue and may cause collateral damage to vision, hearing, growth and learning. Proton beam therapy delivers higher doses of radiation which stop just beyond the tumor and theoretically cause less damage to healthy brain tissue.

    "We were pretty confident in our decision this was going to minimize the side effects - and that was one of our main concerns," said Kelly Keegan, Addison's mother.

    The room where Addison gets her treatment has an area called the gantry. It spins 360 degrees so protons can be delivered from multiple different angles. Those protons come from the cyclotron and come through the snout. The goal is to position those beams to within one millimeter of her tumor.

    It could make a big difference in Addison's brain.

    "I anticipate for this little girl and many others - the less we radiate of normal brain, the better off we're going to be," said Dr. Peter Phillips with the Children's Hospital of Philadelphia.

    Proton therapy has been used on adults for years. This center is the first dedicated to children. It is expensive, averaging about $100,000 - three times more than traditional radiation. It may take a decade to gather conclusive evidence it works.

    "It's better for medicine if we study it over the long run - particularly with such an expensive form of technology," said Dr. Edward Halperin, the dean of the School of Medicine at the University of Louisville.

    At the end of 30 treatments, Addison is bright and focused, showing no side effects.

    "She's running around, just like she was - this is as good as I imagined it would be," said Kelly Keegan.

    Right now, Addison's brain scan looks good. There's no residual tumor. She'll have the scans every three months, and gradually every six months and then annually to make sure her tumor hasn't returned.

    The treatment is expensive - and insurance companies pay for it on a case-by-case basis. Proton therapies are covered by Medicare and Medicaid. Proton centers usually work with families
  • Anorexia brain shrinkage reversible

    Anorexics who lose excessive weight can also see a shrinking in the brain's gray matter. But new research suggests when they reach a healthy body size they also pack on the gray matter volume.
    The eating disorder officially known as anorexia nervosa, in which an individual starves him or herself or binges and purges, can lead to all sorts of problems as the person becomes malnourished.
    "Anorexia nervosa wreaks havoc on many different parts of the body, including the brain," said study team leader Christina Roberto of Yale University. 
    Past research has shown that anorexics who had maintained a healthy body weight for at least a year didn't show significant differences in brain volume compared with their counterparts without an eating disorder, suggesting any neural deficits had been rectified. But how fast the matter returns and how this happens over time were not known.
    Starving brain tissue
    To find out, Roberto and her colleagues used magnetic resonance imaging (MRI) to take pictures of the brains of 32 adult female patients with anorexia nervosa and 21 healthy women without any psychiatric illnesses.
    The anorexic participants were split between two subtypes: those who restrict calories and those who binge eat and purge.
    The patients, who were between the ages of 18 and 45, got brain scans prior to their inpatient weight-gain treatment at the Columbia University Center for Eating Disorders and again once they had reached 90 percent of the ideal body weight.  
    During treatment, they had to meet certain goals each week in terms of weight gain, and they had to eat 100-percent of their food.
    When in a state of starvation, the women with anorexia nervosa had less gray-matter brain volume compared with healthy women. And those who had the illness the longest showed the greatest reductions in brain volume when underweight.
    The average gray-matter volume of anorexics was about 648 milliliters initially, compared with about 680 ml for healthy individuals. While the gray-matter volume stayed constant for healthy participants, it increased to an average of 663 for anorexics at their second scan (when they'd reached the weight benchmark).
    "Within a few weeks a little over a month we started to see that reversal. Their gray matter didn't fully normalize, but another study suggests if a patient maintains that weight over time it probably will fully normalize."
    White matter another matter
    The scans didn't show significant changes in white-matter brain volume. (While gray matter is mostly found on the brain's surface, called the cortex, where brain cells are packed , white matter is buried deep in the brain and is made up primarily of long, spindly appendages of some brain cells.)
    Though anorexia nervosa tends to lead to a decrease in brain volume, Roberto said researchers aren't exactly sure why. "We hypothesize that it's linked to starvation and being in an underweight state. If you starve yourself, that nutrition deficit leads to reduced brain volume," Roberto told LiveScience.

    Modified measles virus may help treat childhood brain tumours

    In a new study, a modified measles virus has shown potential for treating childhood brain tumour known as medulloblastoma.
    Medulloblastoma is the most common malignant central nervous system tumour of childhood, accounting for about 20 percent of paediatric brain tumours.
    These tumours are located in the cerebellum, the area of the brain that controls balance and other complex motor functions. Refinements in treatment have increased the 5-year survival to close to 70 percent, but treatment still involves invasive surgery, radiation therapy and chemotherapy.
    "There is still an urgent need to investigate alternative therapeutic approaches that are more effective and have less toxic side effects," said study lead author Corey Raffel, chief of Neurosurgery at Nationwide Children's Hospital and a faculty member of The Ohio State University College of Medicine.
    Vaccine strains of measles virus have been used to kill tumour cells in a number of tumour types including one type of adult brain tumour. One vaccine strain of measles, the Edmonston strain, targets the cell surface receptor CD46 to gain entry into susceptible cells.
    "This preference most likely explains the efficacy of Edmonston strains in killing tumour cells, given the high level of expression of CD46 in multiple tumour types. It is also the reason we chose to explore a modified Edmonston's strain of measles virus for use in medulloblastoma," said Dr. Raffel.
    The team's laboratory studies revealed that established medulloblastoma cell lines express the measles receptor, CD46 and that medulloblastoma specimens removed from patients have a high level of CD46 expression.
    "Other oncolytic viruses have been explored as possible treatment modalities for medulloblastoma. The fact that all of the surgical medulloblastoma specimens that we examined expressed the measles virus receptor leads us to believe that measles virus may have some advantages over other viruses," said Dr. Raffel.
    Having demonstrated receptor expression, the team treated the medulloblastoma cell lines with the modified measles virus. Within 72 hours, all cell lines exhibited significant tumour cell death.
    The team also administered the modified measles virus to mouse models of medulloblastoma, administering treatment every other day for 10 days.
    By the end of the study period, pathological review of the animals confirmed that two of the animals were free of tumour and the third had a very small amount of residual tumour. In eight of the eleven mice the primary tumour was eradicated.
    "Our study demonstrates that a modified measles virus has therapeutic potential in the treatment of intracerebral medulloblastoma. These results provide initial data to be pursued with additional studies toward the goal of using the virus in a clinical trial for the treatment of medulloblastoma. Measles virus therapy could be applied to the tumour bed following surgical resection to target microscopic residual disease. This approach could potentially alleviate the need for radiation and chemotherapy," said Dr. Raffel.
    The new study appears in Neuro-Oncology.

    A med that reduces brain's response to alcoholism

    A drunk teen.jpg
    A med that reduces brain's response to alcoholism (Getty Images)

    Opioid blocker extended-release injectable naltrexone (XR-NTX) is able to reduce the brain’s response to cues that may cause alcoholics to relapse, researchers at Harvard-affiliated McLean Hospital have reported.

    In data presented at the annual meeting of the American Psychiatric Association, Scott Lukas, PhD, director of the Neuroimaging Center at McLean, located in Belmont, Mass., said the findings help in the understanding of how XR-NTX works in reducing the craving for alcohol and may potentially help predict which people will respond best to the drug.

    "These data are quite important since relapse remains a significant challenge in treating patients with alcohol dependence," Lukas said. "It looks to us that XR-NTX can help people remain abstinent by reducing the importance of these cues so they are less likely to relapse."

    XR-NTX works by blocking opioid receptors in the brain and was approved for the treatment of alcohol dependence in 2006. XR-NTX is commercially available as Vivitrol.

    "We were trying to better understand the biological basis of how XR-NTX reduces alcohol consumption," Lukas said. "These data clearly demonstrate that XR-NTX reduced craving response in the brain when patients were presented with alcohol cues."

    In the study, which has not yet been published, the researchers used brain imaging as a tool to document how XR-NTX works when a person is placed in a situation deemed risky for alcohol relapse.

    Brain Shrinkage in Anorexia is Reversible

    Anorexics who lose excessive weight can also see a shrinking in the brain's gray matter. But new research suggests when they reach a healthy body size they also pack on the gray matter volume.
    The eating disorder officially known as anorexia nervosa, in which an individual starves him or herself or binges and purges, can lead to all sorts of problems as the person becomes malnourished.
    "Anorexia nervosa wreaks havoc on many different parts of the body, including the brain," said study team leader Christina Roberto of Yale University.
    Past research has shown that anorexics who had maintained a healthy body weight for at least a year had significant differences in brain volume compared with their counterparts without an eating disorder. But how fast the matter returns and how this happens over time were not known.
    Starving brain tissue
    To find out, Roberto and her colleagues used magnetic resonance imaging (MRI) to take pictures of the brains of 32 adult female patients with anorexia nervosa and 21 healthy women without any psychiatric illnesses.
    The anorexic participants were split between two subtypes: those who restrict calories and those who binge eat and purge.
    The patients, who were between the ages of 18 and 45, got brain scans prior to their inpatient weight-gain treatment at the Columbia University Center for Eating Disorders and again once they had reached 90 percent of the ideal body weight.  
    During treatment, they had to meet certain goals each week in terms of weight gain, and they had to eat 100-percent of their food.
    When in a state of starvation, the women with anorexia nervosa had less gray-matter brain volume compared with healthy women. And those who had the illness the longest showed the greatest reductions in brain volume when underweight.
    The average gray-matter volume of anorexics was about 648 milliliters initially, compared with about 680 ml for healthy individuals. While the gray-matter volume stayed constant for healthy participants, it increased to an average of 663 for anorexics at their second scan (when they'd reached the weight benchmark).
    "Within a few weeks a little over a month we started to see that reversal. Their gray matter didn't fully normalize, but another study suggests if a patient maintains that weight over time it probably will fully normalize."
    White matter another matter
    The scans didn't show significant changes in white-matter brain volume. (While gray matter is mostly found on the brain's surface, called the cortex, where brain cells are packed, white matter is buried deep in the brain and is made up primarily of long, spindly appendages of some brain cells.)
    Though anorexia nervosa tends to lead to a decrease in brain volume, Roberto said researchers aren't exactly sure why. "We hypothesize that it's linked to starvation and being in an underweight state. If you starve yourself, that nutrition deficit leads to reduced brain volume," Roberto told LiveScience.
    Scientists aren't sure whether or not the brain-volume changes have an impact on cognition, and that's something Roberto would like to look into. There have been reports of cognitive impairment in those with anorexia nervosa, but scientists don't know if it's linked to grey-matter shrinking.
    In terms of full recovery from the disorder, Roberto said overall about one-third of sufferers get better fully, one-third struggle over time, and one-third remain chronically ill. 

    Researcher links autism, testosterone

    Children with autistic traits exposed to high levels of hormone in womb
    Higher testosterone levels in unborn babies can lead to permanent changes in the brain that contribute to the development of autistic traits, new research suggests.
    According to British psychologist Simon Baron-Cohen, autism is the result of an "extreme male brain," leading to a mind that is predominantly hardwired for understanding rules, identifying patterns and building systems.
    In people with autism, such neurological traits tend to be highly developed. A functioning female brain is largely hardwired for empathy -- the ability to read and respond to another person's thoughts or feelings.
    Studies by Baron-Cohen's research team at Cambridge University show children with autistic traits such as low empathy, limited language skills and a highly developed sense of order and routine also tend to have had higher levels of testosterone in the womb.
    Baron-Cohen tested his theory by examining the hormone levels of 235 pregnant women who had amniocentesis to screen for any fetal abnormalities. He then followed the children of these women years after they gave birth.
    Baron-Cohen discovered that compared to children with normal testosterone levels in the womb, children with high fetal testosterone levels had a smaller vocabulary at age two; by age eight, their mothers also noticed that they had lower-than-average levels of empathy and unusually well-developed abilities to identify patterns and details.
    The findings suggest testosterone plays a key role in how the brain develops, Baron-Cohen said Tuesday at an autism conference sponsored by McGill University.
    "Testosterone is a very interesting candidate for how the brain might become masculinized in the general population," said Baron-Cohen, who has spent more than two decades studying autism spectrum disorders.
    Baron-Cohen is among a growing number of neuropsychological researchers who are taking a fresh look at autism. The condition, they say, shouldn't be thought of as a disease to be eradicated. It may be that the autistic brain is simply different -- an example of the variety of human development.
    These researchers assert that the focus on finding a cure for autism -- the disease model -- has kept science from asking fundamental questions about how autistic brains function.
    Indeed, Baron-Cohen points to more effective ways to teach people with autism.
    For example, his Cambridge team has pioneered the use of DVDs to help autistic children read emotional cues in everyday social interactions. The DVDs, The Transporters (www.thetransporters.com) and Mind Reading (www.jkp.com/mindreading), allow children to see actors demonstrating a variety of emotions. Unlike real life, where social interactions are quick and fleeting, DVDs allow children to study methodically and replay the situations that cause different emotions.
    "It's not the natural way that most of us learn about emotions," said Baron-Cohen.
    "Most of us learn about emotions through social interaction in the playground or with our siblings, our families. But here, we're suggesting that maybe children with autism, if they're not picking up emotions in the usual way, might find it easier to learn about emotions through computers. And that's because computers are very predictable, they are rule-governed systems so people with autism might prefer to learn in that format."

    Discovery of stem cell sheds new light on human brain evolution

    London, May 26 (ANI): Scientists at the University of California, San Francisco have found a new stem cell in the developing human brain.

    Future studies of these cells are expected to shed light on developmental diseases such as autism and schizophrenia and malformations of brain development, including microcephaly, lissencephaly and neuronal migration disorders as well as age-related illnesses, such as Alzheimer's disease, the authors added.

    Studies also will allow scientists to track the molecular steps that the cell goes through as it evolves into the nerve cell, or neuron, it produces.

    This information could then be used to prompt embryonic stem cells to differentiate in the culture dish into neurons for potential use in cell-replacement therapy.

    "This discovery has the potential to transform our understanding of the development and evolution of the human neocortex, the most uniquely human part of the central nervous system," said the senior author of the study, neurologist Arnold Kriegstein, director of the Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research at UCSF.

    "It also should inform our understanding of developmental diseases and advance the creation of cell-based therapies. Many neurological diseases develop in neurons or the neural circuits between them. If we're going to understand how these disorders develop, we have to better understand how the human and primate cerebral cortex develops," Kriegstein added.

    The study is reported in a recent issue of the journal Nature.

    Moderate Drinking May Protect Brain From Alzheimer's

    Non-smoking women seem to benefit the most, study finds 
     
    (HealthDay News) -- Moderate drinking may help protect against the onset of Alzheimer's disease among otherwise healthy people, a new Spanish study suggests. Women who don't smoke appear to gain the most benefit from alcohol consumption, according to the research team, from the University of Valencia, the Valencia government and the Municipal Institute of Medical Investigation in Barcelona.
    "Our results suggest a protective effect of alcohol consumption, mostly in non-smokers, and the need to consider interactions between tobacco and alcohol consumption, as well as interactions with gender, when assessing the effects of smoking and/or drinking on the risk of Alzheimer's disease," the study's lead author, Ana M. Garcia, from the University of Valencia's department of preventive medicine and public health, said in a news release.
    "Interactive effects of smoking and drinking are supported by the fact that both alcohol and tobacco affect brain neuronal receptors," Garcia explained.
    The findings, published in the May issue of the Journal of Alzheimer's Disease, are gleaned from a comparative analysis of both the medical background and the smoking and drinking habits among people with Alzheimer's disease stacked up against a group of healthy individuals.
    Both groups were similar in age and in gender breakdown.
    Smoking appeared to have no impact on Alzheimer's risk, the authors found. However, moderate drinking did seem to reduce risk for the disease, particularly among non-smoking women.

    Click here to find out more! Brain Cells May Serve as Clot-Busters

    WEDNESDAY, May 26 (HealthDay News) -- Researchers report that they've discovered how tiny blood vessels remove blood clots from the brain in mice -- a finding that could help scientists gain a better understanding of how to treat people who suffer from Alzheimer's disease and stroke.
    Click here to find out more!
    Removing clots and other blockages in the brain is crucial to allow blood to flow unimpeded, since blockages can lead to a shortage of oxygen, damaged communication between nerve cells and eventual cell death.
    In the new study, researchers at the Northwestern University Feinberg School of Medicine used scanning technology to examine tiny blood vessels -- known as microvessels-- in the brains of mice. They discovered that cells in the walls of the vessels restore blocked blood flow by sealing off the blockages and removing them.
    The blood vessels of older mice weren't as easily able to remove the blockages in the brain.
    "The reduced efficiency of this protective mechanism in the older brain and its effect on the function of nerve cells in the brain may significantly contribute to age-related cognitive decline," researcher Suzana Petanceska, of the National Institute on Aging's Division of Neuroscience, which paid for the research, said in a news release.
    "This may also be part of the mechanism by which vascular risk factors such as high blood pressure and diabetes increase the risk of Alzheimer's disease with age," she added.
    The findings appear online May 26 in the journal Nature.

    Reduced Melatonin Associated With Sleep Disturbance in Traumatic Brain Injury

    A new study using polysomnography confirms sleep disturbances in patients with traumatic brain injury (TBI), including increased wake after sleep onset (WASO) and reduced sleep efficiency, an average of 14 months after their injury compared with healthy control subjects. Other findings, including reduced evening melatonin production in these patients, as well as increased levels of depression and anxiety, may be contributing to these problems. Slow-wave sleep was also higher in patients with TBI vs healthy controls after controlling for depression.
    The researchers, with senior corresponding author Shantha M. W. Rajaratnam, PhD, from the School of Psychology and Psychiatry at Monash University in Australia, propose that depression may be affecting the sleep quality, but the increased slow-wave sleep they observed may be due to the mechanical effects of the brain damage.
    "These results suggest that the brain injury may disrupt the brain structures that regulate sleep, including the production of melatonin," Dr. Rajaratnam said in a statement from the American Academy of Neurology. "Future studies should examine whether taking supplemental melatonin can improve sleep in people with brain injuries."