Brain
During exercise, the human brain shifts into high gear on ‘alternative energy’
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Alternative energy is all the rage in major media headlines, but for the human brain, this is old news. According to a study by researchers from Denmark and The Netherlands published in the October 2008 print issue of The FASEB Journal, the brain, just like muscles, works harder during strenuous exercise and is fueled by lactate, rather than glucose. Not only does this finding help explain why the brain is able to work properly when the body’s demands for fuel and oxygen are highest, but it goes a step further to show that the brain actually shifts into a higher gear in terms of activity. This opens doors to entirely new areas of brain research related to understanding lactate’s specific neurological effects.
“Now that we know the brain can run on lactate, so to speak, future studies should show us when to use lactate as part of a treatment,” said Gerald Weissmann, MD, Editor-in-Chief of The FASEB Journal. “From an evolutionary perspective, the result of this study is a no-brainer. Imagine what could have or did happen to all of the organisms that lost their wits along with their glucose when running from predators. They were obviously a light snack for the animals able to use lactate.”
To reach their conclusion, the researchers looked at research that compared the blood running to and from the heads of volunteers undergoing strenuous exercise. They found that the blood on its way to the brain contained considerably more lactate than blood flowing from the brain.
New marker for raised intracranial pressure
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Magnetic resonance imaging (MRI) measurements of the thickness of the optic nerve sheath are a good marker for raised intracranial pressure (ICP). New research published today in BioMed Central’s open access journal Critical Care shows that a retro-bulbar optic nerve sheath diameter (ONSD) above 5.82mm predicts raised ICP in 90% of cases.
The dural sheath surrounding the optic nerve communicates with the subarachnoid space and distends when ICP is elevated. Thomas Geeraerts, from Addenbrooke’s Hospital, Cambridge, led a team who investigated whether MRI can be used to precisely measure the diameter of the optic nerve and its sheath. He said, “Raised ICP is frequent in conditions such as stroke, liver failure and meningitis. It is associated with increased mortality and poor neurological outcomes. As a result, the early detection and treatment of raised ICP is critical, but often challenging. Our MRI-based technique provides a useful, non-invasive solution”.
The early detection of raised ICP can be very difficult when invasive devices are not available. As the authors report, “Clinical signs of raised ICP such as headache, vomiting and drowsiness are not specific and are often difficult to interpret. In sedated patients, clinical signs frequently appear well after the internal damage has been done. Optic nerve sheath distension could be an early, reactive and sensitive sign of raised ICP”.
Treatment for Parkinson’s examined
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The PhD defended by Juan Carlos Gómez-Esteban at the University of the Basque Country analysed the results of the clinical research undertaken at the Movement Disorders Unit at Cruces Hospital since 1998. It involved a study of the most efficacious surgical operations undertaken and pharmaceutical drugs used to treat these disorders as well genetic studies carried out to date.
The field of movement disorders is one of the most complex branches of neurology. The volume of knowledge acquired is so large that it has needed a number of neurologists to sub-specialise in the matter and multidisciplinary units have been created to tackle problems such as the diagnosis of Parkinson’s Disease and of atypical Parkinsonisms, the choice of the most suitable surgical therapies and pharmaceutical drugs or the carrying out of genetic studies. Thus is 1998 the Movement Disorders Unit at Cruces Hospital in Bilbao was created with neurologists, neurosurgeons, neurophysiologists, anaesthetists, neuropsychologists and radiologists. Since its creation, more than 100 surgical operations have been carried out, the majority on patients with Parkinson’s Disease. Currently it is a centre of reference for functional surgery in the Autonomous Community of the Basque Country (CAPV), and even receives patients from other autonomous communities.
Hypnosis shown to reduce symptoms of dementia
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A scientist at the University of Liverpool has found that hypnosis can slow down the impacts of dementia and improve quality of life for those living with the condition.
Forensic psychologist, Dr Simon Duff, investigated the effects of hypnosis on people living with dementia and compared the treatment to mainstream health-care methods. He also looked at how hypnosis compared to a type of group therapy in which participants were encouraged to discuss news and current affairs.
They found that people living with dementia who had received hypnosis therapy showed an improvement in concentration, memory and socialisation compared to the other two treatment groups. Relaxation, motivation and daily living activities also improved with the use of hypnosis.
Obsessive compulsive disorder linked to brain activity
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Cambridge researchers have discovered that measuring activity in a region of the brain could help to identify people at risk of developing obsessive compulsive disorder (OCD).
As the current diagnosis of OCD is based on a clinical interview and often does not occur until the disorder has progressed, this could enable earlier more objective detection, and intervention.
The scientists, funded by the Medical Research Council and Wellcome Trust, have discovered that people with OCD and their close family members show under-activation of brain areas responsible for stopping habitual behaviour. This is the first time that scientists have associated functional changes in the brain with familial risk for the disorder. Their findings are reported in the 18 July edition of Science.
Alcoholism-associated molecular adaptations in brain neurocognitive circuits
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After many years of heavy drinking, alcohol produces pathological alterations in the brain. In many alcoholics these changes culminate in massive social deterioration and disorders of memory and learning. Severe cognitive impairments occur in approximately 10% of heavy drinkers. Alcoholic dementia is the second leading course of adult dementia in the Western countries, accounting for 10% of the cases, and still represents an unresolved problem. So far no effective pharmacotherapy for memory problems in alcoholics is available.
Nowadays this problem can be approached by innovative research using molecular and epigenetic analyses, which yield new insight into brain pathophysiology.
Molecular dysregulations in endogenous opioids – a neurotransmitter system in the brain that is central to reward function and pain control – are supposed to play a critical role in the development of alcoholism and associated cognitive impairment.
‘Mind’s eye’ influences visual perception
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Letting your imagination run away with you may actually influence how you see the world. New research from Vanderbilt University has found that mental imagery - what we see with the “mind’s eye” - directly impacts our visual perception.
The research was published online June 26 by the journal Current Biology in a paper titled, “The Functional Impact of Mental Imagery on Conscious Perception.”
“We found that imagery leads to a short-term memory trace that can bias future perception,” says Joel Pearson, research associate in the Vanderbilt Department of Psychology. and lead author of the study. “This is the first research to definitively show that imagining something changes vision both while you are imagining it and later on.”
New oral drug curbs MS disease activity
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In people with multiple sclerosis, or MS, treatment with a new immune-modulating drug called laquinimod can significantly reduce disease activity seen on brain MRI scans, a multinational team reports in The Lancet medical journal.
Currently approved drugs that target the inflammation associated with MS are all given by injection, point out Dr. Giancarlo Comi, from the University Vita-Salute in Milan, Italy, and colleagues. By contrast, laquinimod can be taken more conveniently, by mouth.
In a mid-stage clinical trial involving 306 patients with relapsing-remitting MS, Comi’s team investigated the effects of two laquinimod doses—0.3 and 0.6 milligrams daily—compared to an inactive placebo.
Known Genetic Risk for Alzheimer’s in Whites Also Places Blacks at Risk
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A commonly recognized gene that places one at risk for Alzheimer’s disease does not discriminate between blacks and whites, according to new research led by Florida State University.
FSU Psychology Professor Natalie Sachs-Ericsson and graduate student Kathryn Sawyer have found that the gene APOE epsilon 4 allele is a risk factor for African-Americans as well as whites. Until now, it has been a mainstream belief that the gene is only a risk factor for whites.
“The results of our study have clear implications for research and treatment of Alzheimer’s disease,” Sachs-Ericsson said. “The APOE test might be used as one tool in identifying people who are at risk for Alzheimer’s. We now know that African- Americans and Caucasians alike need to be considered for such risk assessments.”
Non-whites Receive Harsher Sentences for Inflicted Traumatic Brain Injury of Children
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Non-white defendants are nearly twice as likely to receive harsher prison sentences than white defendants in North Carolina criminal cases stemming from inflicted traumatic brain injury of young children.
That’s the conclusion reached by researchers from the Injury Prevention Research Center at the University of North Carolina at Chapel Hill, who tracked down what happened in every such case prosecuted in North Carolina in 2000 and 2001. Their study appears in the June issue of the journal Pediatrics.
Inflicted traumatic brain injury is a specific form of child abuse, which includes but is not limited to shaken baby syndrome.
Alzheimer’s brain plaques cleared in mice
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Protein accumulations, or plaques, characteristic of Alzheimer’s disease can be eliminated from the brains of mice, researchers report, by encouraging scavenger immune cells called macrophages to do their work.
The activity of macrophages is damped down by a naturally occurring compound called TGF-beta, to stop runaway reactions, and prior research has shown that brain levels of TGF-beta are increased in patients with Alzheimer’s disease, according to the report in the research journal Nature Medicine.
Some researchers believed that the high levels of TGF-beta were simply an attempt to quiet the inflammatory response associated with Alzheimer plaques. However, the new findings contradict that notion.
When your memories can no longer be trusted
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You went to a wedding yesterday. The service was beautiful, the food and drink flowed and there was dancing all night. But people tell you that you are in hospital, that you have been in hospital for weeks, and that you didn’t go to a wedding yesterday at all.
The experience of false memories like this following neurological damage is known as confabulation. The reasons why patients experience false memories such as these has largely remained a mystery. Now a new study conducted by Dr Martha Turner and colleagues at University College London, published in the May 2008 issue of Cortex offers some clues as to what might be going on.
The authors studied 50 patients who had damage to different parts of the brain, and found that those who confabulated all shared damage to the inferior medial prefrontal cortex, a region in the centre of the front part of the brain just behind the eyes.
Neural cell transplants may help those with Parkinson’s disease
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The current issue of CELL TRANSPLANTATION (Vol. 17:4) features a number of publications by researchers seeking new ways to treat Parkinson’s disease (PD), a neurological disease characterized by muscle rigidity, tremor and slowed physical movements related to insufficient levels of dopamine (DA) in the basal ganglia of the brain, by using primate models to examine the potential therapy role of transplanted cells.
One research team looked at the ability of human neural progenitor cells (hNPCs) as a potential therapy when hNPCs were engineered to produce glial derived neurotrophic factor (GDNF) in the brain following hNPC transplants.
“Localized delivery is essential for aiming therapeutic molecules when treating neurodegenerative disorders,” said Maria Emborg, PhD, of the University of Wisconsin-Madison. “There are currently a number of clinical trials underway using direct gene therapy approaches to deliver potent trophic factors throughout the basal ganglia.”
Weight-loss drugs may harm developing brain: study
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A drug from a new class of weight-loss treatments disrupted wiring needed for brain development in young mice, U.S. researchers said on Wednesday, raising concerns about using such medications in children.
Mark Bear and colleagues at the Massachusetts Institute of Technology studied the effects of a chemical that suppresses appetite by blocking cannabinoid receptors in the brain, the same brain mechanisms that make people hungry when they smoke marijuana.
“I think that the cautionary note is that these mechanisms play an important role in ... brain development,” said Bear, whose study appears in the journal Neuron.
Drinking dulls the brain’s response to threats
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Drinking alcohol dulls the brain’s ability to detect threats, U.S. researchers said on Tuesday in a study that helps explain why people who are drunk cannot tell when the guy at the end of the bar is angling for a fight.
They said the study is the first to show how alcohol affects the human brain as it responds to threats.
“You see this all of the time. People get into confrontations when they are intoxicated that they probably wouldn’t get into when they are sober,” said Jodi Gilman of the National Institutes on Alcohol Abuse and Alcoholism, whose study appears in the Journal of Neuroscience.
