Posts tagged neuroscience
Articles and news from the latest research reports.
How can you measure someone’s pulse, just by pointing a camera at their face? MIT computer scientists have created an algorithm that can do just that, by amplifying the subtle changes in motion and colour in a video.
Read more: Eulerian Video Magnification for Revealing Subtle Changes in the World
Yoga Reduces Stress; Now It’s Known Why
Six months ago, researchers at UCLA published a study that showed using a specific type of yoga to engage in a brief, simple daily meditation reduced the stress levels of people who care for those stricken by Alzheimer’s and dementia. Now they know why.
“The goal of the study was to determine if meditation might alter the activity of inflammatory and antiviral proteins that shape immune cell gene expression,” said Lavretsky. “Our analysis showed a reduced activity of those proteins linked directly to increased inflammation.
“This is encouraging news. Caregivers often don’t have the time, energy, or contacts that could bring them a little relief from the stress of taking care of a loved one with dementia, so practicing a brief form of yogic meditation, which is easy to learn, is a useful too.”
New vision therapy for stroke victims
The innovative vision therapy tool will be used to evaluate and train people with a vision deficit caused by a brain injury or dysfunction.
Each year about 220,000 Australians suffer from an acquired brain injury caused by strokes, car accidents and trauma. Of those, about 30 to 35 per cent acquire neurological vision impairments as a result of damage to the brain, not the eyes, causing many patients to only see half an image.
The software, developed by MDPP Research Associate Dr Fabian Lim, will be trialled by NVT Systems as a new therapeutic product for their clients.
The touch screen tool features five visual tasks with varying degrees of difficulty, including a line-tracing exercise and a shopping catalogue task where the object is to match images in the catalogue with a shopping list.
Dr. Lim said the software would give health care providers a “quantitative measure” for assessing vision deficit, tracking improvements and targeting specific impediments, offering a more effective alternative to traditional pen and paper assessments.
“By repeatedly practicing these exercises patients learn how to scan their surroundings and look for things that might not be in their field of view, and ultimately improve their visual sense,” Dr. Lim said.
NVT Systems is now trialling the simulator software with patients from organisations such as Guide Dogs SA.NT.
NVT Systems Manager Training and Research, Mrs Allison Hayes, said the fantastic work by the Medical Device Partnering Program had enabled the company to expand its product range for local and international markets.
“One of the great things about this new tool is that we will be able to measure important parameters that could be used by carers to map improvements in performance and target specific deficits,” Mrs. Hayes said.
“The visual skills taught using the touch screen device can be transferred to functional activities of daily living, helping our clients to carry out important everyday activities in the home and community.”
Computers may help patients restore movement after stroke
New research suggests that patients whose mobility has been limited by stroke may one day use their imagination and a computer link to move their hands.
Leuthardt
In patients, scientists at Washington University School of Medicine in St. Louis have shown they can detect the brain simply thinking about moving a partially or completely paralyzed hand. The half of the brain that normally thinks such thoughts and moves the hand can no longer do so because of stroke damage. Instead, the signal comes from the undamaged half of the brain.
The new study suggests it may be possible to harness these signals to restore a fuller range of movement in the patient’s limbs.
“We’ve known for some time that the brain can reroute or otherwise adapt its circuits to cope with an injury,” says senior author Eric Leuthardt, MD, associate professor of neurosurgery, of biomedical engineering and of neurobiology. “Now we have proof-of-principle that we can use technology to aid that process.”
To demonstrate the potential to help restore movement, scientists connected brain signals detected by an electrode-studded cap to the movements of a cursor on a computer screen. In 30 minutes or less, patients learned to control the movement of the cursor with thoughts of moving their impaired hand. Researchers are now working on a motorized glove that will make the imagined movements a reality.
The results are available online in The Journal of Neural Engineering.
Leuthardt, who is director of Washington University’s Center for Innovation in Neuroscience and Technology, is a pioneer in the field of brain-computer interfaces, or devices that allow the brain to communicate directly with computers to restore abilities lost to injury or disease.
Much of Leuthardt’s research has focused on patients with epilepsy who are undergoing surgery to remove the part of the brain where their seizures originate. He uses the electrode grids temporarily implanted on the surface of the brain to pinpoint areas where the seizures begin. With the patients’ permissions, Leuthardt also uses the implants to gather and analyze detailed information on brain activity for future use in brain-computer interfaces. This approach laid the foundations for the technique now being applied to the stroke population.
In the new research, first author David Bundy, a graduate student, worked with four patients who had suffered strokes that caused extensive damage on one side of the brain. All were experiencing paralysis or significant difficulty moving the hand on the opposite side of the body.
The brain signals that control movement are low-frequency signals, which makes them relatively easy to detect with electrodes on the outside of the skull. Researchers fitted patients with an electrode-studded cap connected to a computer, and asked them to perform a finger-tapping activity. Depending on a cue flashed on a screen in front of them, the patients either tapped the fingers of their unimpaired hand or imagined tapping the fingers of the impaired hand. Scientists used the cap to identify signals in healthy part of the brain that accompanied the imaginary movements.
The researchers are now developing motorized braces that can be controlled by similar signals, with the goal of restoring full movement in weak or paralyzed limbs.
“This is an exciting development that opens up new opportunities to help even more patients overcome limitations imposed by brain damage or degeneration,” Leuthardt says.
Californian biotech firm Life Technologies is the first team to register for the $10 million (£6.4m) Archon Genomics X Prize, which will be a race to sequence the genomes of 100 centenarians.
The prize was first announced in 2006, and is a joint effort between the X Prize Foundation and geneticist J Craig Venter. It’s supposed to stimulate the development of less expensive sequencing technologies, and establish a clinical standard for DNA research.
Interested parties have until May 2013 to register. Late that year, in September, each team will have 30 days to sequence the genomes of 100 people, at a cost of $1,000 (£643) or less.
The DNA has been donated by 100 100 year old people from all over the world, to make the competition “scientifically valuable and more meaningful to the general public”. That way, the prize can double up as medical research into the science of healthy aging and longevity.
Life Technologies’ secret weapon is the Ion Proton Sequencer, which it describes as a “semiconductor device that enables chemical signals to be directly translated into digital information for the first time” — a bit like the CMOS imager in an iPhone, which turns photons into electrons.
"It would have cost $100 million and taken 33 years to meet this challenge when the competition was announced in 2006," said Jonathan Rothberg, CEO and founder of Life Technology’s Ion Torrent brand. "The Ion Proton sequencer is designed to sequence a human genome for $1,000 in just a few hours."
Source: Wired
The authors of the article have added another dimension to this illusion of body ownership. Using virtual reality they have shown that a virtual body with one very long arm can be incorporated into body representation. An arm up to three or possibly even four times the length of a person’s real arm can be felt as if it was the person’s own arm. This is notwithstanding the fact that having one such long arm introduces a gross asymmetry in the body. An extended body space (a body with longer limbs occupies more volume than a normal body) affects also the special space surrounding our body that is called peripersonal space — a space that when violated by objects or other people can be experienced as a threat or intimacy, depending on the context.
In the experiment 50 people experienced virtual reality where they had a virtual body. They put on a head-mounted display so that all around themselves they saw a virtual world. When they looked down towards where their body should be, they saw a virtual body instead of their real one. They had their dominant hand resting on a table with a special textured material that they could feel with their real hand, but also see their virtual hand touching it. So as they moved their real hand over the surface of this table they would see the virtual hand doing the same.
The results of the study were analysed by using a questionnaire to assess the subjective illusion that the virtual arm was part of the person’s body; a pointing task, where the arm that did not grow in length was required to point towards where the other hand was felt to be (with eyes shut), and a response to a threat task, in which a saw fell down towards the virtual hand (figure E, F) and it was measured whether people would move their real hand in an attempt to avoid it.
Based on these data, researchers found that people did have the illusion that the extended hand was their own. Even when the virtual arm was 4 times the length of the corresponding real arm, still 40-50% of participants showed signs of incorporation of the virtual arm as part of their body representation. It was also found that vision alone is a very powerful inducer of the illusion of virtual arm ownership — those who experienced the inconsistent condition where the virtual hand did not touch the table, even though the real hand felt the table top, had a strong illusion of ownership over the virtual arm.
These results show how malleable is our body representation, even incorporating strong asymmetries in the body shape, which do not correspond at all to the average human shape. This type of research will help neuroscientists to understand how the brain represents the body, and ultimately may help people overcome illnesses that are based on body image distortions.
New drug could treat Alzheimer’s, multiple sclerosis and brain injury
July 24, 2012
A new class of drug developed at Northwestern University Feinberg School of Medicine shows early promise of being a one-size-fits-all therapy for Alzheimer’s disease, Parkinson’s disease, multiple sclerosis and traumatic brain injury by reducing inflammation in the brain.
Northwestern has recently been issued patents to cover this new drug class and has licensed the commercial development to a biotech company that has recently completed the first human Phase 1 clinical trial for the drug.
The drugs in this class target a particular type of brain inflammation, which is a common denominator in these neurological diseases and in traumatic brain injury and stroke. This brain inflammation, also called neuroinflammation, is increasingly believed to play a major role in the progressive damage characteristic of these chronic diseases and brain injuries.
By addressing brain inflammation, the new class of drugs — represented by MW151 and MW189 — offers an entirely different therapeutic approach to Alzheimer’s than current ones being tested to prevent the development of beta amyloid plaques in the brain. The plaques are an indicator of the disease but not a proven cause.
A new preclinical study published today in the Journal of Neuroscience, reports that when one of the new Northwestern drugs is given to a mouse genetically engineered to develop Alzheimer’s, it prevents the development of the full-blown disease. The study, from Northwestern’s Feinberg School and the University of Kentucky, identifies the optimal therapeutic time window for administering the drug, which is taken orally and easily crosses the blood-brain barrier.
"This could become part of a collection of drugs you could use to prevent the development of Alzheimer’s," said D. Martin Watterson, a professor of molecular pharmacology and biological chemistry at the Feinberg School, whose lab developed the drug. He is a coauthor of the study.
In previous animal studies, the same drug reduced the neurological damage caused by closed-head traumatic brain injury and inhibited the development of a multiple sclerosis-like disease. In these diseases as well as in Alzheimer’s, the studies show the therapy time window is critical.
How a Single Brain Trauma May Lead to Alzheimer’s Disease
ScienceDaily (July 24, 2012) — A study, performed in mice and utilizing post-mortem samples of brains from patients with Alzheimer’s disease, found that a single event of a moderate-to-severe traumatic brain injury (TBI) can disrupt proteins that regulate an enzyme associated with Alzheimer’s. The paper, published in The Journal of Neuroscience, identifies the complex mechanisms that result in a rapid and robust post-injury elevation of the enzyme, BACE1, in the brain. These results may lead to the development of a drug treatment that targets this mechanism to slow the progression of Alzheimer’s disease.
"A moderate-to-severe TBI, or head trauma, is one of the strongest environmental risk factors for Alzheimer’s disease. A serious TBI can lead to a dysfunction in the regulation of the enzyme BACE1. Elevations of this enzyme cause elevated levels of amyloid-beta, the key component of brain plaques associated with senility and Alzheimer’s disease," said first author Kendall Walker, PhD, postdoctoral associate in the department of neuroscience at Tufts University School of Medicine (TUSM).
Building on her previous work, neuroscientist Giuseppina Tesco, MD, PhD, of Tufts University School of Medicine (TUSM), led a research team that first used an in vivo model to determine how a single episode of TBI could alter the brain. In the acute phase (first two days) following injury, levels of two intracellular trafficking proteins (GGA1 and GGA3) were reduced, and an elevation of BACE1 enzyme level was observed.
Next, in an analysis of post-mortem brain samples from patients with Alzheimer’s disease, the researchers found that GGA1 and GGA3 levels were reduced while BACE1 levels were elevated in the brains of Alzheimer’s disease patients compared to the brains of people without Alzheimer’s disease, suggesting a possible inverse association.
In an additional experiment using a mouse strain genetically modified to express the reduced level of GGA3 that was observed in the brains of Alzheimer’s disease patients, the team found that one week following traumatic brain injury, BACE1 and amyloid-beta levels remained elevated even when GGA1 levels had returned to normal. The research suggests that reduced levels of GGA3 were solely responsible for the increase in BACE 1 levels and therefore the sustained amyloid-beta production observed in the sub-acute phase, or seven days, after injury.
"When the proteins are at normal levels, they work as a clean-up crew for the brain by regulating the removal of BACE1 enzymes and facilitating their transport to lysosomes within brain cells, an area of the cell that breaks down and removes excess cellular material. BACE1 enzyme levels may be stabilized when levels of the two proteins are low, likely caused by an interruption in the natural disposal process of the enzyme," said Tesco, assistant professor of neuroscience at Tufts School of Medicine and member of the neuroscience program faculty at the Sackler School of Graduate Biomedical Sciences at Tufts.
"We found that GGA1 and GGA3 act synergistically to regulate BACE1 post-injury. The identification of this interaction may provide a drug target to therapeutically regulate the BACE1 enzyme and reduce the deposition of amyloid-beta in Alzheimer’s patients," she continued. "Our next steps are to confirm these findings in post-mortem brain samples from patients with moderate-to-severe traumatic brain injuries."
Moderate-to-severe TBIs are caused most often by traumas, such as severe falls or motor vehicle accidents, that result in a loss of consciousness. Not all traumas to the head result in a TBI. According to the Centers for Disease Control and Prevention, each year 1.7 million people sustain a TBI. Concussions, the mildest form of a TBI, account for about 75% of all TBIs. Studies have linked repeated head trauma to brain disease and some previous studies have linked single events of brain trauma to brain disease, such as Alzheimer’s. Alzheimer’s disease currently affects as many as 5.1 million Americans and is the most common cause of dementia in adults age 65 and over.
Source: Science Daily
Brain discovery sheds light on link between vision and emotion
Neuroscientists have discovered a new area of the brain that is uniquely specialised for peripheral vision and could be targeted in future treatments for panic disorders and Alzheimer’s disease.
Published today in high impact journal Current Biology, researchers led by Dr Hsin-Hao Yu and Professor Marcello Rosa from Monash University’s Department of Physiology found that a brain area, known as prostriata, was specialised in detecting fast-moving objects in peripheral vision.
This area, located in a primitive part of the cerebral cortex, has characteristics unlike any other visual area described before, including a “direct line” of communication to brain areas controlling emotion and quick reactions.
Dr Yu said the discovery, identified during the development of the Monash Vision Group’s bionic eye, funded through the ARC Research in Bionic Vision Science and Technology Initiative, could lead to new treatments for panic disorders such as agoraphobia (fear of open spaces) and may extend into other medical areas including Alzheimer’s treatment.
“The brain is the most complex organ in the human body and perhaps the most remarkable. These findings change how we think of the brain in terms of how visual information is processed,” Dr Yu said.
“This area is likely to be hyperactive in panic disorder, with agoraphobia. This knowledge could lead to treatment options for the hyperactivity, and therefore sensitivity to such disorders, particularly the fear of open spaces.
“Correlation with previous studies also shows that prostriata is one of the first areas affected in Alzheimer’s disease. This knowledge helps to explain spatial disorientation and the tendency to fall, which are among the earliest signs of a problem associated with Alzheimer’s.”
Professor Rosa said this area had ultra-fast responses to visual stimuli, simultaneously broadcasting information to brain areas that control attention, emotional and motor reactions. This challenges current conceptions of how the brain processes visual information.
“This suggests a specialised brain circuit through which stimuli in peripheral vision can be fast-tracked to command quickly coordinated physical and emotional responses,” Professor Rosa said.
Chronic pain distorts sufferers’ sense of space and time
July 24, 2012
Einstein’s famous theory of relativity proposed that matter can distort space and time. Now a new study recently published in the journal Neurology suggests that chronic pain can have the same effect.
Neuroscientists from the University of South Australia, Neuroscience Research Australia and the University of Milano Bicocca in Italy, studied people with chronic back pain, the most common painful condition which costs western countries billions of dollars in lost productivity every year.
They presented identical vibration stimuli to the painful area and a non-painful area and noted that the stimuli were processed more slowly by the brain if they came from the painful area.
The most striking finding, however, was that the same effect occurred if the stimuli were delivered to a healthy body part being held near the painful area.
Lead author of the study, Professor Lorimer Moseley from the University of South Australia, says it was not altogether surprising that, in people with chronic pain, there are changes in the way the brain processes information from and about the painful body part.
“But what is remarkable is that the problem affects the space around the body as well as the body itself,” Prof Moseley says.
Experiments showed that if a hand was held near the painful area of the back, the brain would almost ‘neglect’ that hand.
“The potential similarity between our findings and the time-space distortion predicted by the relativity theory is definitely intriguing,” Prof Moseley says.
“Obviously, here it is not external space that is distorted but the ability of the brain to represent that space within its neural circuitry.
“This finding opens up a whole new area of research into the way the brain allows us to interact with the world and how this can be disrupted in chronic pain.”
Provided by University of South Australia
Source: medicalxpress.com