Researchers at Monash University in Melbourne, Australia, have observed atypical neurophysiological activity in amputees who experience synesthetic pain (pain synesthetes) when observing pain in another.
The researchers found that reduced alpha and theta brainwaves in pain synesthetes may reflect inhibition of normal inhibitory mechanisms (neurotransmitters involved in the processing of observed pain) as well as increased synesthetic pain.
The researchers used EEG to record brain activity in eight amputees who experienced both phantom and synesthetic pain, 10 amputees who experienced just phantom pain, and 10 healthy people with no amputations while they looked at images of hands or feet in potentially painful and non-painful situations.
When viewing the images, the researchers found that the pain synesthetes exhibited decreased theta and alpha brainwaves compared with the other volunteers. The researchers said that such a decrease reflects an increase in neural activity, suggesting that their mirror systems (neurons that fire when an animal observes the same action performed by another) are activated more strongly.
They said the traumatic experience associated with losing a limb may heighten the sensitivity of pain synesthetes to others’ pain. When threatened, our body naturally becomes hypervigilant to pain: our pain threshold lowers, which can make even small triggers painful. Pain synesthesia may be a symptom of an abnormal, ongoing hypervigilance, the researchers said.
Showing posts with label Science. Show all posts
Showing posts with label Science. Show all posts
Wednesday, June 1, 2011
Wednesday, May 25, 2011
‘Survival protein’ protects the brain against effects of stroke
A “survival protein” that protects the brain against the effects of stroke in rodent brain tissue has been discovered by scientists at Johns Hopkins University. The finding has implications for treating stroke as well as Parkinson’s Disease, diabetes, and heart attack.
When brain tissue is subjected to a stressful but not lethal insult, a defense response occurs that protects cells from subsequent insult. The scientists dissected this preconditioning pathway to identify the most critical molecular players, including the Iduna protein. This protein increased three- to four-fold in preconditioned mouse brain tissue following an insult to the tissue, the scientists said.
The team exposed mouse brain cells to short bursts of a toxic chemical, and then screened these “preconditioned” cells for genes that turned on as a result of the insult. Focusing on Iduna, the researchers turned up the gene’s activity in the cells during exposure to the toxic chemical, which induced preconditioning. Cells deficient in Iduna did not survive, but those with more Iduna did.
The scientists found that the Iduna protein interferes with a particular kind of cell death that’s implicated in complications from diabetes and heart attack as well as stroke. By binding with a molecule known as PAR polymer, Iduna prevents the movement of cell-death-inducing factor (AIF) into a cell’s nucleus.
“Apparently, what doesn’t kill you makes you stronger,” says Valina Dawson, Ph.D. “This protective response was broad in its defense of neurons and glia and blood vessels — the entire brain. It’s not just a delay of death, but real protection that lasts for about 72 hours.”
When brain tissue is subjected to a stressful but not lethal insult, a defense response occurs that protects cells from subsequent insult. The scientists dissected this preconditioning pathway to identify the most critical molecular players, including the Iduna protein. This protein increased three- to four-fold in preconditioned mouse brain tissue following an insult to the tissue, the scientists said.
The team exposed mouse brain cells to short bursts of a toxic chemical, and then screened these “preconditioned” cells for genes that turned on as a result of the insult. Focusing on Iduna, the researchers turned up the gene’s activity in the cells during exposure to the toxic chemical, which induced preconditioning. Cells deficient in Iduna did not survive, but those with more Iduna did.
The scientists found that the Iduna protein interferes with a particular kind of cell death that’s implicated in complications from diabetes and heart attack as well as stroke. By binding with a molecule known as PAR polymer, Iduna prevents the movement of cell-death-inducing factor (AIF) into a cell’s nucleus.
“Apparently, what doesn’t kill you makes you stronger,” says Valina Dawson, Ph.D. “This protective response was broad in its defense of neurons and glia and blood vessels — the entire brain. It’s not just a delay of death, but real protection that lasts for about 72 hours.”
Monday, May 16, 2011
‘Master switch’ gene for obesity and diabetes discovered
A gene linked to type 2 diabetes and cholesterol levels is in fact a “master regulator” gene that controls the behavior of other genes found within fat in the body, researchers at King’s College London and the University of Oxford have found.
The researchers examined over 20,000 genes in subcutaneous fat biopsies from 800 UK female twin volunteers.
They found an association between the KLF14 gene (inherited from the mother) and the expression levels of multiple distant genes found in fat tissue. This means that it acts as a master switch to control these genes, the researchers said. This was then confirmed in a further independent sample of 600 subcutaneous fat biopsies from Icelandic subjects.
Other genes controlled by KLF14 are in fact linked to a range of metabolic traits, including body-mass index (obesity), cholesterol, insulin and glucose levels, highlighting the interconnectedness of metabolic traits, the researchers said.
The researchers examined over 20,000 genes in subcutaneous fat biopsies from 800 UK female twin volunteers.
They found an association between the KLF14 gene (inherited from the mother) and the expression levels of multiple distant genes found in fat tissue. This means that it acts as a master switch to control these genes, the researchers said. This was then confirmed in a further independent sample of 600 subcutaneous fat biopsies from Icelandic subjects.
Other genes controlled by KLF14 are in fact linked to a range of metabolic traits, including body-mass index (obesity), cholesterol, insulin and glucose levels, highlighting the interconnectedness of metabolic traits, the researchers said.
Tuesday, February 22, 2011
A new high-resolution method for imaging below the skin using a liquid lens
University of Rochester optics professor Jannick Rolland has developed an optical technology that provides unprecedented images under the skin’s surface.
The aim of the technology is to detect and examine skin lesions to determine whether they are benign or cancerous without having to cut the suspected tumor out of the skin and analyze it in the lab. Instead, the tip of a roughly one-foot-long cylindrical probe is placed in contact with the tissue, and within seconds a clear, high-resolution, 3D image of what lies below the surface emerges.
Rolland presented her findings at the 2011 annual meeting of the American Association for the Advancement of Science in Washington, D.C., on Feb. 19.
“My hope is that, in the future, this technology could remove significant inconvenience and expense from the process of skin lesion diagnosis,” Rolland says. “When a patient walks into a clinic with a suspicious mole, for instance, they wouldn’t have to have it necessarily surgically cut out of their skin or be forced to have a costly and time-consuming MRI done. Instead, a relatively small, portable device could take an image that will assist in the classification of the lesion right in the doctor’s office.”
The device accomplishes this using a unique liquid lens setup developed by Rolland and her team for a process known as Optical Coherence Microscopy. In a liquid lens, a droplet of water takes the place of the glass in a standard lens. As the electrical field around the water droplet changes, the droplet changes its shape and therefore changes the focus of the lens. This allows the device to take thousands of pictures focused at different depths below the skin’s surface. Combining these images creates a fully in-focus image of all of the tissue up to 1 millimeter deep in human skin, which includes important skin tissue structures. Because the device uses near infrared light instead of ultrasounds, the images have a precise, micron-scale resolution instead of a millimeter-scale resolution.
The process has been successfully tested in in-vivo human skin and several papers on it have been published in peer-reviewed journals. Rolland says that the next step is to start using it in a clinical research environment so its ability to discriminate between different types of lesions may be assessed.
The aim of the technology is to detect and examine skin lesions to determine whether they are benign or cancerous without having to cut the suspected tumor out of the skin and analyze it in the lab. Instead, the tip of a roughly one-foot-long cylindrical probe is placed in contact with the tissue, and within seconds a clear, high-resolution, 3D image of what lies below the surface emerges.
Rolland presented her findings at the 2011 annual meeting of the American Association for the Advancement of Science in Washington, D.C., on Feb. 19.
“My hope is that, in the future, this technology could remove significant inconvenience and expense from the process of skin lesion diagnosis,” Rolland says. “When a patient walks into a clinic with a suspicious mole, for instance, they wouldn’t have to have it necessarily surgically cut out of their skin or be forced to have a costly and time-consuming MRI done. Instead, a relatively small, portable device could take an image that will assist in the classification of the lesion right in the doctor’s office.”
The device accomplishes this using a unique liquid lens setup developed by Rolland and her team for a process known as Optical Coherence Microscopy. In a liquid lens, a droplet of water takes the place of the glass in a standard lens. As the electrical field around the water droplet changes, the droplet changes its shape and therefore changes the focus of the lens. This allows the device to take thousands of pictures focused at different depths below the skin’s surface. Combining these images creates a fully in-focus image of all of the tissue up to 1 millimeter deep in human skin, which includes important skin tissue structures. Because the device uses near infrared light instead of ultrasounds, the images have a precise, micron-scale resolution instead of a millimeter-scale resolution.
The process has been successfully tested in in-vivo human skin and several papers on it have been published in peer-reviewed journals. Rolland says that the next step is to start using it in a clinical research environment so its ability to discriminate between different types of lesions may be assessed.
Wednesday, January 12, 2011
Blood vessels for lab-grown tissues
Researchers from Rice University and Baylor College of Medicine (BCM) have broken one of the major roadblocks on the path to growing transplantable tissue in the lab: They’ve found a way to grow the blood vessels and capillaries needed to keep tissues alive.
Saturday, July 24, 2010
Chicken Came Before the Egg: "Scientific Proof"
British scientists claim to have solved one of the great mysteries of life, the universe and everything in it: The chicken came before the egg, they say, and they're not mincing words.
"It had long been suspected that the egg came first, but now we have the scientific proof that shows that in fact the chicken came first," Sheffield University's Dr Colin Freeman, according to a report in the Metro.
Researchers from Scotland and England used a supercomputer called HECToR to look in such detail at a chicken eggshell that they were able to determine the vital role of a protein used to kick-start the egg's formation.
That protein is only found, wait for it... inside a chicken.
Freeman, who worked on HECToR with counterparts at Edinburgh's Warwick University, said the protein had been identified earlier by scientists and was known to be linked to egg formation, "but by examining it closely we have been able to see how it controls the process," he added, describing it as a catalyst.
Professor John Harding, who also took part in the research, told Metro the discovery could have other applications.
"Understanding how chickens make shells is fascinating in itself, but can also give clues towards designing new materials." he said.
Which is good, because in spite of HECToR's hard work and the "scientific proof" it yielded, the study offered no explanation as to how the chicken got there in the first place.
If not from an egg, perhaps it just came from across the road.
"It had long been suspected that the egg came first, but now we have the scientific proof that shows that in fact the chicken came first," Sheffield University's Dr Colin Freeman, according to a report in the Metro.
Researchers from Scotland and England used a supercomputer called HECToR to look in such detail at a chicken eggshell that they were able to determine the vital role of a protein used to kick-start the egg's formation.
That protein is only found, wait for it... inside a chicken.
Freeman, who worked on HECToR with counterparts at Edinburgh's Warwick University, said the protein had been identified earlier by scientists and was known to be linked to egg formation, "but by examining it closely we have been able to see how it controls the process," he added, describing it as a catalyst.
Professor John Harding, who also took part in the research, told Metro the discovery could have other applications.
"Understanding how chickens make shells is fascinating in itself, but can also give clues towards designing new materials." he said.
Which is good, because in spite of HECToR's hard work and the "scientific proof" it yielded, the study offered no explanation as to how the chicken got there in the first place.
If not from an egg, perhaps it just came from across the road.
Friday, March 26, 2010
Why HOT water freezes quicker than COLD water
HOT water sometimes freezes faster than cold water - but why? This peculiar phenomenon has baffled scientists for generations, but now there is evidence that the effect may depend on random impurities in the water.
Fast-freezing of hot water is known as the Mpemba effect, after a Tanzanian schoolboy called Erasto Mpemba (see "How the Mpemba effect got its name"). Physicists have come up with several possible explanations, including faster evaporation reducing the volume of hot water, a layer of frost insulating the cooler water, and differing concentration of solutes. But the answer has been very hard to pin down because the effect is unreliable - cold water is just as likely to freeze faster.
James Brownridge, who is radiation safety officer for the State University of New York at Binghamton, believes that this randomness is crucial. Over the past 10 years he has carried out hundreds of experiments on the Mpemba effect in his spare time, and has evidence that the effect is based on the shifty phenomenon of supercooling.
"Water hardly ever freezes at 0 °C," says Brownridge. "It usually supercools, and only begins freezing at a lower temperature." The freezing point depends on impurities in the water which seed the formation of ice crystals. Typically, water may contain several types of impurity, from dust particles to dissolved salts and bacteria, each of which triggers freezing at a characteristic temperature. The impurity with the highest nucleation temperature determines the temperature at which the water freezes.
Brownridge starts with two samples of water at the same temperature - say, tap water at 20 °C - in covered test tubes and cools them in a freezer. One will freeze first, presumably because its random mix of impurities give it a higher freezing point.
If the difference is large enough, the Mpemba effect will appear. Brownridge selects the sample with the higher natural freezing temperature to heat to 80 °C, warming the other to only room temperature, then puts the test tubes back in the freezer. The hot water will always freeze faster than the cold water if its freezing point is at least 5 °C higher, Brownridge says.
It may seem surprising that moving the finish line by only 5 °C makes enough of a difference, when the hotter sample starts out 60 °C behind in the race. But the bigger the temperature difference between an object and its surroundings - in this case, the freezer - the faster it cools. So the hot sample will do most of its cooling very quickly, helping it to reach its own freezing point of -2 °C, say, before the cooler water gets to its freezing point of -7 °C.
Fast-freezing of hot water is known as the Mpemba effect, after a Tanzanian schoolboy called Erasto Mpemba (see "How the Mpemba effect got its name"). Physicists have come up with several possible explanations, including faster evaporation reducing the volume of hot water, a layer of frost insulating the cooler water, and differing concentration of solutes. But the answer has been very hard to pin down because the effect is unreliable - cold water is just as likely to freeze faster.
James Brownridge, who is radiation safety officer for the State University of New York at Binghamton, believes that this randomness is crucial. Over the past 10 years he has carried out hundreds of experiments on the Mpemba effect in his spare time, and has evidence that the effect is based on the shifty phenomenon of supercooling.
"Water hardly ever freezes at 0 °C," says Brownridge. "It usually supercools, and only begins freezing at a lower temperature." The freezing point depends on impurities in the water which seed the formation of ice crystals. Typically, water may contain several types of impurity, from dust particles to dissolved salts and bacteria, each of which triggers freezing at a characteristic temperature. The impurity with the highest nucleation temperature determines the temperature at which the water freezes.
Brownridge starts with two samples of water at the same temperature - say, tap water at 20 °C - in covered test tubes and cools them in a freezer. One will freeze first, presumably because its random mix of impurities give it a higher freezing point.
If the difference is large enough, the Mpemba effect will appear. Brownridge selects the sample with the higher natural freezing temperature to heat to 80 °C, warming the other to only room temperature, then puts the test tubes back in the freezer. The hot water will always freeze faster than the cold water if its freezing point is at least 5 °C higher, Brownridge says.
It may seem surprising that moving the finish line by only 5 °C makes enough of a difference, when the hotter sample starts out 60 °C behind in the race. But the bigger the temperature difference between an object and its surroundings - in this case, the freezer - the faster it cools. So the hot sample will do most of its cooling very quickly, helping it to reach its own freezing point of -2 °C, say, before the cooler water gets to its freezing point of -7 °C.
Monday, January 4, 2010
Douglas Smith mechanically stretches living nerves to grow resilient transplants
In a lab at the University of Pennsylvania, a plastic dish holds two rows of tiny black dots, pairs of them connected by dozens of thin, hairlike filaments. Each dot is a cluster of thousands of neurons, explains Douglas Smith, who is a professor of neurosurgery and the director of Penn's Center for Brain Injury and Repair. The fibers that stretch between them actually comprise thousands of axons, long, slender projections that conduct electrical impulses away from each neuron's central body. These bundles--each one a lab-engineered nerve--represent physical bridges that Smith hopes will help researchers like him mend previously irreparable injuries.
To make the long nerve transplants, Smith and his team first collect sensory neurons--cells that transmit information to the brain--from the spinal cords of fetal rats. Research technician Kevin Browne then pipettes a gelatinous pink protein called collagen onto two adjacent films in a specially built chamber. About the size of a shoebox, it houses a stretching apparatus made up of a vertical block attached to metal rods. One of the small, clear films, called the towing membrane, is suspended at one end by the block and curves down almost to the base of the chamber, where it overlaps the second membrane. Browne places one set of neurons in the collagen on the towing membrane and another on the bottom membrane. At this point, the two groups are less than 100 micrometers--two hairs' width--apart. He puts the whole setup into a humming incubator that runs at 37 °C, mimicking the internal temperature of a rat.
To make the long nerve transplants, Smith and his team first collect sensory neurons--cells that transmit information to the brain--from the spinal cords of fetal rats. Research technician Kevin Browne then pipettes a gelatinous pink protein called collagen onto two adjacent films in a specially built chamber. About the size of a shoebox, it houses a stretching apparatus made up of a vertical block attached to metal rods. One of the small, clear films, called the towing membrane, is suspended at one end by the block and curves down almost to the base of the chamber, where it overlaps the second membrane. Browne places one set of neurons in the collagen on the towing membrane and another on the bottom membrane. At this point, the two groups are less than 100 micrometers--two hairs' width--apart. He puts the whole setup into a humming incubator that runs at 37 °C, mimicking the internal temperature of a rat.
Sunday, November 22, 2009
Friday, May 8, 2009
Estrogen controls how the brain processes sound
Scientists at the University of Rochester have discovered that the hormone estrogen plays a pivotal role in how the brain processes sounds.
The findings, published in today's issue of The Journal of Neuroscience, show for the first time that a sex hormone can directly affect auditory function, and point toward the possibility that estrogen controls other types of sensory processing as well. Understanding how estrogen changes the brain's response to sound, say the authors, might open the door to new ways of treating hearing deficiencies.
Previous studies have hinted at a connection between estrogen and hearing in women who have low estrogen, such as often occurs after menopause, says Pinaud. No one understood, however, that estrogen was playing such a direct role in determining auditory functions in the brain, he says. "Now it is clear that estrogen is a key molecule carrying brain signals, and that the right balance of hormone levels in men and women is important for reasons beyond its role as a sex hormone," says Raphael Pinaud, assistant professor of brain and cognitive sciences at the University of Rochester and lead author of the study.
The findings, published in today's issue of The Journal of Neuroscience, show for the first time that a sex hormone can directly affect auditory function, and point toward the possibility that estrogen controls other types of sensory processing as well. Understanding how estrogen changes the brain's response to sound, say the authors, might open the door to new ways of treating hearing deficiencies.
Previous studies have hinted at a connection between estrogen and hearing in women who have low estrogen, such as often occurs after menopause, says Pinaud. No one understood, however, that estrogen was playing such a direct role in determining auditory functions in the brain, he says. "Now it is clear that estrogen is a key molecule carrying brain signals, and that the right balance of hormone levels in men and women is important for reasons beyond its role as a sex hormone," says Raphael Pinaud, assistant professor of brain and cognitive sciences at the University of Rochester and lead author of the study.
Wednesday, April 15, 2009
First Cloned Camel
The United Arab Emirates on Tuesday claimed its own version of Dolly the sheep, the world's first cloned mammal, after the birth of a cloned camel in Dubai this month.
"This is the first cloned camel in the world," said Dr Nisar Wani, researcher at the Camel Reproduction Centre.
Injaz, a female one-humped camel, was born on April 8 after more than five years of work by scientists at the Camel Reproduction Centre and the Central Veterinary Research Laboratory, The National newspaper reported.
"This significant breakthrough in our research programme gives a means of preserving the valuable genetics of our elite racing and milk producing camels in the future," Dr Lulu Skidmore, scientific director at the Camel Reproduction Centre, said in a statement.
Injaz, whose name means achievement in Arabic, is the clone of a camel that was slaughtered for its meat in 2005, the National said.
Scientists used DNA extracted from cells in the ovaries of the slain animal and put it into an egg taken from the surrogate mother to create a reconstructed embryo, it said.
Dolly was born in 1996 in Edinburgh in what was regarded as one of the world's most significant scientific breakthroughs, but was put to sleep in 2003.
Thursday, January 29, 2009
First Commercially Cloned Dog
Well you knew it was gonna happen but who knew how soon it would be. BioArts International announced today that they have delivered the world’s first commercially cloned dog, a 10-week old Labrador named Lancey, to a Florida family. According to the press release issued by the company, “BioArts International is a biotech company focused on unique, untapped markets in the global companion animal, stem cell and human genomics industries.She is a cutey though!
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