Monday, December 26, 2011

Now, a prosthetic device to help the blind see

Now, a prosthetic device to help the blind see London: Scientists have developed a new prosthetic device that sends images directly to the brain, a technology they say could be used to help blind humans in less than a decade.

The device, which was developed by a team at the Weill Medical College of Cornell University and tested on animals, takes information from the outside world and decodes it into a pattern that the brain can "read" as an image.

Neuroscientist Sheila Nirenberg, who led the research, explained that the key was converting the data into patterns of electrical activity for the brain to process.

What's more, Nirenberg said, it could be used to help blind humans in less than a decade, the Daily Mail reported.

She said: "I study how the brain uses patterns of electrical activity to see, to hear, to reach for an object.

"I've been starting to use what we've learned about these patterns of electricity to develop prosthetic devices."

Prof Nirenberg explained that if a person has a retinal disease, there's very little that can be done for them, with drug treatments only effective on a small number of sufferers.

There are prosthetic devices, but they only allow patients to see simple images, mainly just outlines.

But the new device is something "that could make a difference", Prof Nirenberg explained at a seminar in San Diego recently.

She told the audience that the retina contains circuits that process images, but that these circuits can die from disease.

The device she's pioneered "mimics the action of the front end circuitry of the retina", enabling images to be fired to the brain once more.

So far it's only been tested on mice, but when asked if it could be adapted for humans in 10 years, she replied: "I'm hoping less."

Understanding the Brain: Research Could Help Paralyzed Patients

Neuroscience has come a long way since the days of Aristotle, who thought that the main function of the brain was to cool the blood. In the 18th century we learned that externally applied electricity could propagate within neurons; in the 19th century we found out that the cerebral hemispheres of rabbits and monkeys had underlying electrical activity; in the early 20th century the first human electroencephalogram (EEG) was recorded; and less than a decade into the 21st century we already had consumer-based EEG products. Scientists have developed sophisticated methods to read, amplify, and understand neuronal activity in the brain, but complex technical challenges remain. Each cubic millimeter of brain tissue can contain up to 100,000 neurons, so even the most sensitive and miniscule of electrode sensors is still "listening" to hundreds or thousands of often distinct signals.
The field may have just become more precise because scientists at the Norwegian University of Life Sciences have developed "detailed mathematical models revealing the connection between nerve cell activity and the electrical signal recorded by an electrode." Reported this month in Neuron, the research focused on the spatial distribution of a specific type of low frequency signal called the low field potential (LFP) and the results are summarized here:
The size of the generating region depends on the neuron morphology, the synapse distribution, and the correlation in synaptic activity. For uncorrelated activity, the LFP represents cells in a small region (within a radius of a few hundred micrometers). If the LFP contributions from different cells are correlated, the size of the generating region is determined by the spatial extent of the correlated activity.
In terms of applications, the press release discusses diseases and disorders for which this enhanced model may prove useful:
Better understanding of the electrical brain signals may directly influence diagnosing and treatment of illnesses such as epilepsy.
"Electrodes are already being used to measure brain cell activity related to seizures in epilepsy patients, as well as planning surgical procedures. In the future, LFP signals measured by implanted electrodes could detect an impending epilepsy seizure and stop it by injecting a suitable electrical current," Einevoll says.
"A similar technique is being used on many Parkinson's patients, who have had electrodes surgically implanted to prevent trembling," researcher Klas Pettersen at UMB adds.
Einevoll and Pettersen also outline treatment of patients paralysed by spinal cord fracture as another potential area where the method can be used.
"When a patient is paralysed, nerve cells in the cerebral cortex continue to send out signals, but the signals do not reach the muscles, and the patient is thus unable to move arms or legs. By monitoring the right nerve cells and forwarding these signals to for example a robot arm, the patient may be able to  steer by his or her thoughts alone," Einevoll says.

'Rare' Brain Disorder May Be More Common Than Thought, Say Mayo Clinic Scientists

JACKSONVILLE, Fla., Dec 25, 2011 (BUSINESS WIRE) -- A global team of neuroscientists, led by researchers at Mayo Clinic in Florida, have found the gene responsible for a brain disorder that may be much more common than once believed. In the Dec. 25 online issue of Nature Genetics, the researchers say they identified 14 different mutations in the gene CSF1R that lead to development of hereditary diffuse leukoencephalopathy with spheroids (HDLS). This is a devastating disorder of the brain's white matter that leads to death between ages 40 and 50. People who inherit the abnormal gene always develop HDLS.
The finding is important because the researchers suspect that HDLS is more common than once thought. According to the study's senior investigator, neurologist Zbigniew Wszolek, M.D., a significant number of people who tested positive for the abnormal gene in this study had been diagnosed with a wide range of other conditions. These individuals were related to a patient known to have HDLS, and so their genes were also examined.
"Because the symptoms of HDLS vary so widely -- everything from behavior and personality changes to seizures and movement problems -- these patients were misdiagnosed as having either schizophrenia, epilepsy, frontotemporal dementia, Parkinson's disease, multiple sclerosis, stroke, or other disorders," says Dr. Wszolek. "Many of these patients were therefore treated with drugs that offered only toxic side effects.
"Given this finding, we may soon have a blood test that can help doctors diagnose HDLS, and I predict we will find it is much more common than anyone could have imagined," he says.
Dr. Wszolek is internationally known for his long-term effort to bring together researchers from around the world to help find cases of rare brain disorders and discover their genetic roots.
Dr. Wszolek's interest in HDLS began when a severely disabled patient came to see him in 1995 and mentioned that other members of his family were affected. He was able to definitively diagnose the disease upon autopsy of the patient because of changes in the white matter. Until then, only one family in Sweden had been diagnosed with HDLS.
Dr. Wszolek began to search for other cases, and his Mayo Clinic colleague, Dennis Dickson, M.D., a pathologist, recalled seeing such changes in a brain while he was in training. Dr. Dickson located two more cases in Florida and Michigan, and Dr. Wszolek began to talk about HDLS at every research presentation he made throughout the world. He soon had brain samples from Norway, the United Kingdom, and Canada, and from different areas in the U.S. He and his team of investigators and collaborators have since published numerous studies describing the disorder and have held five international meetings on HDLS.
In this study, which included 38 researchers from 12 institutions in five countries, the study's first author, Rosa Rademakers, Ph.D., led the effort to find the gene responsible for HDLS. Her laboratory studied DNA samples from 14 families in which at least one member was diagnosed with HDLS and compared these with samples from more than 2,000 disease-free participants. The gene was ultimately found using a combination of traditional genetic linkage studies and recently developed state-of-the art sequencing methods. Most family members studied -- who were found to have HDLS gene mutations -- were not diagnosed with the disease, but with something else, thus emphasizing the notion that HDLS is an underdiagnosed disorder.
The CSF1R protein is an important receptor in the brain that is primarily present in microglia, a type of immune cells. "We identified a different CSF1R mutation in every HDLS family that we studied," says Dr. Rademakers. "All mutations are located in the kinase domain of CSF1R which is critical for its activity, suggesting that these mutations may lead to deficient microglia activity. How this leads to the loss of brain cells in HDLS patients is not yet understood, but we now have an important lead to study."
"With no other disease have we found so many affected families so quickly," says Dr. Wszolek. "That tells me this disease is not rare, but quite common."
He adds, "It is fantastic that you can start an investigation with a single case and end up, with the help of many hands, in what we believe to be a world-class gene discovery."
The study was funded by a Mayo benefactor and the Mayo Foundation. Additionally, Mayo Clinic in Florida is a Morris K. Udall Parkinson's Disease Research Center of Excellence supported by the National Institute of Neurological Disorders and Stroke.
About Mayo Clinic
Mayo Clinic is a nonprofit worldwide leader in medical care, research, and education for people from all walks of life. For more information, visit and .
SOURCE: Mayo Clinic
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Less meal may save brain from aging

Rome: Eating less may keep the mind young, according to Italian scientists who say they have discovered the molecular process by which a strict diet may save the brain from the ravages of age.
The research, published in the US journal the Proceedings of the National Academy of Sciences on Monday, is based on a study of mice that were fed a diet of about 70 per cent of the food they normally consumed. Scientists found the calorie-restricted diet triggered a protein molecule, CREB1 that activates a host of genes linked to longevity and good brain function.
“Our hope is to find a way to activate CREB1, for example through new drugs, so to keep the brain young without the need of a strict diet”, said lead author Giovambattista Pani, researcher at the Institute of General Pathology, Faculty of Medicine at the Catholic University of Sacred Heart in Rome.
Researchers have previously discovered that mice on diets showed better cognitive abilities and memory, were less aggressive, and tended to avoid or delay Alzheimer’s disease. But they have not known exactly why. CREB1 is known to regulate important brain functions such as memory, learning and anxiety control, and its activity is reduced or physiologically compromised by ageing, said the study.
Mice that were genetically altered to lack CREB1 showed none of the same memory benefits if they were on a low-calorie diet as mice that had the molecule, and showed the same brain disabilities as mice that were overfed. Thus, our findings identify for the first time an important mediator of the effects of diet on the brain, Pani said. This discovery has important implications to develop future therapies to keep our brain young and prevent brain degeneration and the ageing process.
According to Marc Gordon, chief of neurology at Zucker Hillside Hospital in Glen Oaks, New York, the findings could shed new light on why some people who are obese in middle age encounter cognitive problems later in life. Mid-life obesity has been associated with late-life dementia. However, the physiological basis for this association remains unclear,’ said Gordon, who was not part of the study.
These investigators have studied the effects of limiting caloric intake in mice, and have identified a biochemical pathway that may mediate at least some of the brain’s responses to dietary restriction

Organ donation to immortalise brain-dead college student

Swarna suffered brain injury after fall from college terrace
Swarna Jaswant, 22, will continue to live even after her death. This second year student of Vogue Institute of Technology, Doddaballapur, was declared brain-dead on December 23 at Columbia Asia Hospital, after a fall from the college terrace.

Swarna’s parents have decided to donate her organs after doctors at the hospital found that she failed to respond to brain stem reflexes.

Swarna had a fatal fall on December 14, while walking on the college terrace. She slipped and fell on the glass roof, landing on her head. The girl suffered a brain stem injury and a deep cut on her left thigh. Doctors at the hospital said since Swarna had landed on her head, her chances of recovery were very minimal.

“Following her brain scan, we found that there was severe bleeding in her brain stem, which had a direct link to her heart and lungs and she was put on a ventilator.

On December 22, she did not respond to light reflexes, which is one of the conditions to declare her brain-dead,” said Dr R Chinnadurai, intensivist at the hospital.

The doctor said they counselled Swarna’s parents, who readily agreed for organ donation.

Her mother said she was happy that her daughter would live through someone else. Swarna’s two corneas, two kidneys, liver and heart valves will be transplanted to six recipients.
Following Swarna’s comatose state after the fall, her classmates and parents had staged a protest in the college, but the college authorities did not respond.

“I owe her a doughnut,” is what Meghana Reddy had to say about her best friend.

“Swarna was fond of sugar doughnuts and she had asked me to bring them from my mother’s bakery. This was the last conversation I had with her. She wanted to be a designer and travel the world, she never ever fought with anyone,”said a tearful Meghana.
Swarna’s classmates have stopped attending classes ever since the incident and are helping her parents raise funds for her treatment.

Anand Reddy, the parent of one of the students, said the college authorities were least bothered about the incident.

“The chairman is absconding and we even tried to file an FIR in the police station. If Swarna’s family wants to pursue the case, we will be with them,” he said.

Swarna is survived by her father Jaswant, mother Hemalatha and elder brother Swaroop, who are natives of Mangalore.