Temporary blindness ‘helps hearing’


Temporary blindness ‘helps hearing’

Scientists in the US expect the findings could help those with hearing loss

Temporary blindness can improve hearing, a new study has shown.

Scientists have discovered that keeping mice in the dark for several days altered their brain circuit and made their hearing better.

Researchers now predict humans that humans will respond in the same way, because mammals have a similar brain structure in the region that controls these senses.

The phenomenon has been called the “Ray Charles effect,” as the soul singer and pianist was thought to have more sensitive hearing because of his blindness.

Researchers from the US reported in the journal ‘Neuron’ that neural connections in the brain that control vision and hearing work together to support the other sense.

The findings could be used to help people with hearing loss, and the distressing “ringing” in the ears known as tinnitus.

Dr Hey-Kyoung Lee, a leading member of the team from the Mind/Brain Institute at the Johns Hopkins University in the US, said: “In my opinion, the coolest aspect of our work is that the loss of one sense – vision – can augment the processing of the remaining sense, in this case, hearing, by altering the brain circuit, which is not easily done in adults.

“By temporarily preventing vision, we may be able to engage the adult brain to now change the circuit to better process sound, which can be helpful for recovering sound perception in patients with cochlear implants for example.”

In the study, healthy adult mice were placed in a darkened environment for six to eight days, to simulate blindness, while their brain activity and response to sound was monitored.

When the mice were reintroduced to the light, their vision was unchanged, but their hearing was better than before.

As the researchers played a series of one-note tones, neurons in the auditory cortex involved in hearing fired faster and more powerfully than normal. They were also more sensitive to quiet sounds and better at discriminating between different sounds.

In addition the mice developed more nerve connections, or synapses, between the thalamus – a part of the brain that acts as a “switchboard” for sensory information – and the auditory cortex.

Co-author Dr Patrick Kanold, from the US University of Maryland, said: “We don’t know how many days a human would have to be in the dark to get this effect, and whether they would be willing to do that. But there might be a way to use multi-sensory training to correct some sensory processing problems in humans.”

After returning to normal lighting conditions the mice reverted to their usual standard of hearing in a few weeks.

In the next phase of their five-year study, the scientists plan to look for ways to make the sensory improvements permanent and to expand their scope beyond changes to individual neurons.

Advertisements

Scientists move closer to stem cell cure for type 1 diabetes.


Researchers say they have reversed equivalent of type 1 diabetes in mice using stem cell transplants
Insulin injection

Type 1 diabetes usually leads to a lifetime of insulin injections.

Scientists believe they may have moved a step closer to a cure for the type of diabetes that develops in childhood and usually leads to a lifetime of insulin injections.

Researchers in California report that they have reversed the equivalent of type 1 diabetes in mice through transplants of stem cells. Their experiments have replaced cells in the pancreas damaged by the disease that are unable to make insulin.

Without insulin, the body has difficulty absorbing sugars such as glucose from the blood. The disease usually first shows in childhood or early adulthood and used to be a killer, but glucose levels can now be monitored and regulated with insulin injections.

Scientists have long wanted to try to replace the damaged ß-cells that normally produce insulin. This has been one of the prime targets of stem cell experiments. But until now, it has proved difficult, partly because mature ß-cells do not readily regenerate.

Writing in the journal Cell Stem Cell, scientists at the Gladstone Institutes in San Francisco describe how they took a step back and collected skin cells, called fibroblasts, from laboratory mice. Then, by treating the fibroblasts with a unique “cocktail” of molecules and reprogramming factors, they transformed the cells into endoderm-like cells. Endoderm cells are a type of cell found in the early embryo, and which eventually mature into the body’s major organs – including the pancreas. “Using another chemical cocktail, we then transformed these endoderm-like cells into cells that mimicked early pancreas-like cells, which we called PPLCs,” said the Gladstone postdoctoral scholar Ke Li, the paper’s lead author. “Our initial goal was to see whether we could coax these PPLCs to mature into cells that, like ß-cells, respond to the correct chemical signals and – most importantly – secrete insulin. And our initial experiments, performed in a petri dish, revealed that they did.”

The team then injected these cells into mice that had been genetically modified to have high glucose levels, mimicking the type 1 diabetes condition in humans.

“Importantly, just one week post-transplant, the animals’ glucose levels started to decrease, gradually approaching normal levels,” said Li. “And when we removed the transplanted cells, we saw an immediate glucose spike, revealing a direct link between the transplantation of the PPLCs and reduced hyperglycemia [high glucose level].”

Eight weeks after the transplantation, the scientists found that the pancreas-like cells had turned into the real thing – fully functional insulin-secreting ß-cells had developed in the mice.

The team says this is proof of principle, which one day might be used to cure type 1 diabetes in humans. “I am particularly excited about the prospect of translating these findings to the human system,” said Matthias Hebrok, one of the study’s authors and director of the UCSF Diabetes Center. “Most immediately, this technology in human cells could significantly advance our understanding of how inherent defects in ß-cells result in diabetes, bringing us notably closer to a much-needed cure.”

Pain ‘dimmer switch’ discovered


 

Pain killers
About one in five people suffer from acute or chronic pain

Pain sensitivity is controlled by a genetic “dimmer switch”, which can be re-set, UK scientists have discovered.

Twins sharing 100% of genes have different pain thresholds, which can potentially be altered by lifestyle or medication, say researchers at King’s College, London.

The study could lead to new painkillers or lifestyle interventions, they report in Nature Communications.

One in five of the population suffers from acute or chronic pain.

“Start Quote

“Using drugs or changes in lifestyle we could be able to reset that [pain] thermostat allowing that person in the future to feel less pain”

Tim SpectorProfessor of Genetic Epidemiology at King’s College London

Lead researcher Dr Jordana Bell said the potential to regulate genes involved in pain sensitivity “is very exciting and could lead to a more effective pain relief treatment for patients suffering with chronic pain”.

Sensitivity to pain is complex, with wide individual variation. Previous studies have suggested about half of the influence is explained by genes.

To identify levels of sensitivity to pain, scientists tested 25 pairs of identical twins using a heat probe placed on the arm.

Identical twins share 100% of their genes; therefore any difference between identical twins must be due to their environment or changes affecting the function of their genes.

Study participants were asked to press a button when the heat became painful for them, which allowed the researchers to determine their pain thresholds.

Using DNA sequencing, the researchers examined the whole genetic codes (genomes) of the twins and compared them with 50 unrelated individuals.

The research team found chemical changes within nine genes involved in pain sensitivity that were different in one twin but not in her identical sister.

These were most significant within a known pain sensitivity gene, which is already a target for the development of new painkillers.

Research into the switching on and off of genes, a process known as epigenetic regulation, is a big growth area for the development of new medicines.

‘Landmark’ study

Tim Spector, professor of genetic epidemiology at King’s College London, said epigenetic switching is “like a dimmer switch for gene expression”.

“This landmark study shows how identical twins, when combined with the latest technology to look at millions of epigenetic signals, can be used to find the small chemical switches in our genes that make us all unique – and in this case respond to pain differently.”

The chemical changes act like a “thermostat” or “dimmer switch” to set an individual’s pain sensitivity, Prof Spector added.

“Using drugs or changes in lifestyle, we might be able to reset that thermostat, allowing that person in the future to feel less pain,” he told BBC News.

“The epigenetic changes are potentially reversible.”

CBT ‘effective’ in schizophrenia


Cognitive behavioural therapy session

Changing the way people think about and deal with schizophrenia is a moderately effective treatment, say researchers.

Cognitive behavioural therapy is an officially recommended treatment, but is available to less than 10% of patients in the UK with schizophrenia.

A study published in the Lancet indicates CBT could help the many who refuse antipsychotic medication. Experts say larger trials are needed.

About four-in-10 patients benefit from taking antipsychotic medication.

But the drugs do not work for the majority and they cause side-effects such as type 2 diabetes and weight gain.

Up to half of patients with schizophrenia end up not taking the drugs.

The study looked at cognitive behaviour therapy in 74 people.

The therapy works by identifying an individual patient’s problem – such as hearing voices, paranoid thinking or no longer going out of the house – and developing techniques to deal with them.

“Start Quote

This study suggests that there may be a better option and that offering CBT is better than just leaving such patients to languish”

Prof Robin Murray

Prof Tony Morrison, director of the psychosis research unit at Greater Manchester West Mental Health Foundation Trust, said: “We found cognitive behavioural therapy did reduce symptoms and it also improved personal and social function and we demonstrated very comprehensively it is a safe and acceptable therapy.”

CBT had a moderate effect which was roughly similar to the effect size of antipsychotics – although a head-to-head study directly comparing the two therapies have not been made.

Douglas Turkington, professor of psychiatry at Newcastle University, said: “One of our most interesting findings was that when given the option, most patients were agreeable to trying cognitive therapy.”

He added that drugs and cognitive therapy combined were the best treatment.

But while nearly everyone will be offered drugs, only a small proportion have access to cognitive behaviour therapy.

Prof Robin Murray, from the Institute of Psychiatry at King’s College London, said: “Many patients don’t like to take antipsychotics in the long term, this is not surprising as they have significant side-effects.

“So what to do for patients with continued psychotic symptoms who don’t want to take antipsychotics?

“Until now little was done except lecture them on how silly this was, with the usual result that the patients would simply stop attending.

“This study suggests that there may be a better option and that offering CBT is better than just leaving such patients to languish.”

Temporary blindness ‘boosts hearing’


Daredevil
Fictional superhero Daredevil gained heightened senses after going blind

Temporary blindness heightens hearing and has potential as a therapy for some deaf people, animal research suggests.

A study, published in the journal Neuron, showed keeping mice in the dark for a week changed their brains and enhanced hearing.

The effect lasted for several weeks after they were returned to the light.

Experts said it was a “fascinating” finding, but making more permanent brain alterations would be key to any new treatments for hearing loss.

The US team at Johns Hopkins University and the University of Maryland compared the hearing of mice that had been kept in complete darkness for a week with that of others getting natural light.

Those kept in the dark could hear softer sounds and there were changes in the structure of the auditory cortex in the brain.

“It was quite a surprise to us,” said Dr Patrick Kanold, from Maryland.

One thought was that part of the brain being used for vision was being repurposed, but it seemed the sections dedicated to hearing were being beefed-up.

“Start Quote

There is a burgeoning science in auditory training and developing ways to learn to listen better, it’s a real hot topic.”

Dr Michael AkeroydMRC Institute of Hearing Research

Dr Kanold told the BBC’s Inside Science Programme: “We are not growing any new neurons we are simply strengthening existing connections in the auditory cortex.”

“This really give us hope that there might be some potential to apply this in humans, the nice thing is we don’t need drugs, so it’s relatively straightforward to test.

“This might have implications in deaf people, there’s a variety of people that receive cochlear implants as an adult and it might be the case that this enhances the success of these cochlear implants.”

It is not certain if the same brain changes would take place in people or if they could reverse the declines associated with old age.

Dr Michael Akeroyd, from the Medical Research Council’s Institute of Hearing Research, in Glasgow, told the BBC: “I thought, ‘Ooh this is interesting.’ I don’t know if it’s practical, but it’s got potential.”

He said putting old people with hearing loss into dark rooms for a week or more was unlikely to happen, but that the study added to a growing awareness that there was more to hearing than just the ear.

“Some of most exciting research is that hearing is not just hearing it’s listening, there is a burgeoning science in auditory training and developing ways to learn to listen better, it’s a real hot topic,” he said.

“I would suggest looking for permanent changes next, if you can make it permanent then you’re onto a winner.”

Dr Ralph Holme, the head of biomedical research at the charity Action on Hearing Loss, said: “This is a fascinating study that tells us more about how our sensory systems interact, in this case how blindness can enhance hearing.

“It is important research because once the mechanisms involved are understood it may be possible to develop training or even pharmacological approaches to boosting these processes to help people with hearing loss.

“More research is now needed to establish if similar findings can be observed in humans and whether or not these changes actually lead to better hearing in the real world.”

Measles global deaths decline by 78%.


Child being given a measles vaccine in India
Vaccinating children has helped to reduce deaths from measles worldwide

Global deaths from measles dropped 78% between 2000 and 2012, the World Health Organization estimates.

New figures from the WHO suggest that around 13.8 million deaths were prevented during this time and reported cases declined by 77%.

Good routine immunisation levels and campaigns to vaccinate children are thought to be behind the figures.

But the WHO says measles is still a global threat and some populations remain unprotected.

The mortality estimates from the WHO show that annual measles deaths decreased from more than 562,000 in 2000 to 122,000 in 2012.

Reported cases of measles worldwide declined from 853,480 to 226,722 over the same time.

“Start Quote

There is much more work to be done as more than 330 deaths (mainly among children) still occur daily from measles ”

Karen MahThe Measles and Rubella Initiative

Currently, 84% of the world’s infants receive the first dose of measles vaccine before their first birthday, according to the WHO.

It says that 145 countries have also introduced a routine second dose of measles vaccine to ensure immunity and prevent outbreaks.

Mass campaigns against measles in 2012 resulted in a further 145 million children being vaccinated against the disease, taking the total number of vaccinated children to more than one billion since 2000.

Threat continues

However, there are still concerns that despite this good news, measles remains a worldwide threat.

The regions of Africa, south-east Asia and Europe all experienced large outbreaks in 2012, and the Americas region had to deal with many imported measles cases.

The Democratic Republic of Congo saw the largest measles outbreak of 2012, with 72,029 reported cases. There were around 18,000 cases in India and 12,000 in Ukraine, while the UK experienced just over 2,000 measles cases.

The WHO says the Africa, Eastern Mediterranean and European regions are not likely to meet their measles elimination targets on time.

Without improved immunisation coverage, outbreaks will continue to occur, it says.

Karen Mah, a spokeswoman for The Measles and Rubella Initiative, a global partnership led by the WHO and UNICEF among others, said there were still too many children dying.

“While estimated measles deaths have dropped significantly since 2000, there is much more work to be done as more than 330 deaths (mainly among children) still occur daily from measles.

“We need to move beyond an 84% global routine immunisation coverage. It’s also vital that parents are fully aware of the benefits of immunisation and the risks associated with not vaccinating children,” she added.

The Measles and Rubella Initiative wants to reduce measles deaths by 95% by 2015 and get rid of measles and rubella in at least five regions of the world by 2020.

Giant jellyfish found in Australia.


The jellyfish washed up in Tasmania in January 2014The jellyfish was found by the Lim family as they walked on the beach

Scientists in Australia are working to classify a new species of giant jellyfish that washed up on a beach in Tasmania.

A family found the 1.5m (5ft) jellyfish on a beach south of Hobart last month.

Dr Lisa-ann Gershwin, of Australia’s CSIRO government agency, said that scientists had known about the species for a while but had not yet classified it.

She described the specimen as a “truly magnificent animal”.

Experts at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) were alerted to the discovery by Josie Lim and her family, who came across it.

“She and her children found the jellyfish and took this amazing photo that just boggles the mind,” jellyfish expert Dr Gershwin said.

This species was part of the Lion’s Mane group, she said.

These jellyfish “look like a dinner plate with a mop hanging underneath – they have a really raggedy look to them”, she said.

The Tasmanian discovery was found stranded belly-up, Dr Gershwin explained.

It was one of a “species I’ve known about for a while but it’s not yet named and classified”, she said. “We’re very eager to know more about it.”

It is one of three new species of Lion’s Mane in Tasmania which the scientist is currently working to classify.

Recent years had seen “huge blooms” of jellyfish in Tasmanian waters, she said, but scientists were not sure why.

“We’re very keen to find out why jellyfish are blooming in such super-abundances in these southern waters,” she said.

The world’s largest jellyfish shares the same genus – Cyanea – as the Lion’s Mane. Found in the North Atlantic and Arctic, the Cyanea Arctica can grow up to 3m (10ft) across the body, Dr Gershwin said.

‘No leukaemia risk’ from power lines


Power lines

Children who live near overhead power lines do not have an increased risk of developing leukaemia, a study has said.

Data on 16,500 children who developed leukaemia in Britain between 1962 and 2008 was analysed.

The paper found no increased leukaemia risk for those living near power lines from the 1980s onwards – but a higher risk did exist in the 1960s and 70s.

The researchers said the findings were “reassuring” but work was being done to understand the historical patterns.

Leukaemia accounts for around a third of all cancers diagnosed in children.

Around 460 new cases of leukaemia are diagnosed in children under the age of 15 each year in Britain.

Historic risk

This research, by the Childhood Cancer Research Group at the University of Oxford, used cancer information drawn from the National Registry of Childhood Tumours.

The study, funded by Children with Cancer UK, included nearly 16,500 children born in Britain who were diagnosed with leukaemia between 1962 and 2008.

They were compared with around 20,000 children who were born in the same area who did not develop cancer.

“Start Quote

Until we can explain what caused the increased risk in the earlier decades, we can’t rule out the possibility that in some circumstances there could be a risk”

Kathryn BunchResearcher

When the data for the whole period was analysed it showed no increased risk from living near power lines. However, when the analysis was broken down into decades, an historic increased risk was seen for those born in the 1960s and 70s, who lived within about one-third of a mile (600m) of a power line.

Those born from the 1980s onwards did not have an increased risk.

The researchers say this “strongly suggests” there is no direct biological effect of power lines on leukaemia risk.

Kathryn Bunch, who led the study, said: “It’s very encouraging to see that in recent decades there has been no increased risk of leukaemia among children born near overhead power lines.

“More research is needed to determine precisely why previous evidence suggested a risk prior to 1980, but parents can be reassured from the findings of this study that overhead power lines don’t increase their child’s risk of leukaemia.”

‘Could be risk’

She told the BBC: ” I would like to stress it’s very encouraging that this study gives such reassuring information to parents.

“But I have to be honest, until we can explain what caused the increased risk in the earlier decades, we can’t rule out the possibility that in some circumstances there could be a risk.”

Dr Julie Sharp, Cancer Research UK’s head of health information, said: “There has been a lot of concern that overhead power lines could increase the risk of cancer, particularly leukaemia, in children.

“This study is reassuring for anxious parents, as it indicates that overhead power lines don’t cause leukaemia or other cancers in children.”

The researchers say they do not know for certain why the historic increased risk existed.

They are carrying out further research looking at whether there has been a change in the pollutants emitted: if the spike was in some way connected to the construction of the power lines and has since diminished – or if there has been a shift in the characteristics of the people who live near power lines, as increased leukaemia risk has been linked to higher economic status.

Salmon born with ‘magnetic map’


Chinook salmon
Scientists believe the fish are born with an innate sense of the Earth’s magnetic field

There is more evidence that salmon use the Earth’s magnetic field to perform extraordinary feats of navigation.

A study suggests that Pacific salmon are born with an in-built “magnetic map” that helps them to migrate over thousands of kilometres.

US researchers believe the fish are sensing changes in the intensity and angle of the Earth’s magnetic field to establish their position in the ocean.

The study is published in the journal Current Biology.

The epic journey of the Pacific salmon is one of nature’s greatest migrations.

“Start Quote

It’s like they have a map. They know something about where they are based on what field they are in”

Dr Nathan PutmanOregon State University

The fish hatch inland in rivers and streams, before swimming for hundreds or even thousands of kilometres to reach the open ocean.

After several years of foraging at sea, they make their way back to the same freshwater sites where they spawn and then die.

Lead author Dr Nathan Putman, from Oregon State University, said: “The migration is a lot of effort and it is definitely challenging, and looking at it from the outside, it doesn’t seem necessarily intuitive how they could manage that.”

Turn north

Previous research has suggested that the fish use the Earth’s magnetic field to find their way, with an earlier study led by Dr Putman revealing that Sockeye salmon may possess a memory of the magnetic field where they first entered the sea to find their way back home to their spawning ground.

But now the team says that the fish may also have an innate sense of the world’s magnetic field.

Chinook salmon
The researchers changed the magnetic field and watched how the fish reacted

To investigate, they looked at Chinook salmon hatchlings, which had not yet made a migration out to sea.

Because the intensity and inclination of the Earth’s magnetic field change depending on where you are on the globe, the researchers exposed the fish to the sorts of magnetic fields they might experience on their journey through the ocean.

“We put the fish in buckets, we change the magnetic field around them, and the fish change direction in response to the field,” explained Dr Putman.

For example, if they altered the magnetic field so it mimicked the northern extreme of the salmon’s range, the fish oriented south. If they changed the field so it was the same as that experienced by salmon at the very southern end of their range, the fish turned around and pointed north.

Dr Putman explained: “To try to observe meaningful behaviour in the lab, we needed to have a good prediction of what the fish should do. Since none of these fish are found north of a certain magnetic field, we assumed that they are happiest to the south of that.

“So if they are using the magnetic field to find out where they are, they should think, ‘Oh I am a bit north of where I should be’, and go south. And likewise with the southern magnetic field.”

He added: “It’s like they have a map. They know something about where they are based on what field they are in.”

Because the fish that were studied had never before made a migration, the scientists think the fish are born with this magnetic sense rather than it being a skill that is learned.

The team believes other sea creatures such as turtles, sharks and whales may also use the same tactics to roam the oceans.

‘No target’ in UK animal tests plan.


Laboratory mice

The UK government has launched its delivery plan to replace, refine and reduce the use of animals in research – known as “the 3Rs”.

It pledges to encourage scientists to use alternatives wherever possible.

But there is no commitment in the strategy released on Friday to reduce the total number of animal experiments, which has been on the rise.

This is despite a post-election pledge by the Coalition to cut the use of animals in scientific research.

Instead, the government will promote new, more ethical research techniques which can help boost UK science.

“This isn’t about a numerical target,” said David Willetts, Minister for Universities and Science.

“The commitment is to ‘work to reduce use of animals’. Ultimately the final figure will depend on patterns of scientific advance.

“Britain is a world leader in science but also in concern for the welfare of animals. What we are doing is bringing these two great British traditions together.

“We are absolutely committed to the 3Rs.”

‘Artificial’ focus

Crime Prevention Minister Norman Baker, who is leading the Home Office work, said it would be “artificial” to focus on the absolute numbers of animal experiments.

“Had work not been done via the 3Rs we’d already have a higher number,” he said.

“If we are attracting scientists from overseas because of our good scientific base, that will impact the total figure.

“Minimising the use of animals can also be an opportunity for the science sector.

“I challenge you to find a document like this anywhere else in the world.”

However, the British Union for the Abolition of Vivisection (Buav), which campaigns to end animal testing, called the strategy a “missed opportunity”.

Buav’s chief executive, Michelle Thew, said: “This is a whitewash and shows that the Government has in reality given up on what it promised to do and that is to reduce the number of animal experiments.

“This broken promise is a missed opportunity for the Government to make meaningful and lasting change for the millions of animals that are suffering in UK laboratories.”

Jan Creamer, chief executive of the National Anti-Vivisection Society (Navs) commented: “Incredibly, the Government report admits the failings of animal research, yet claims to be powerless to move towards what it calls the ‘better, faster and cheaper non-animal approaches’.”

Continued rise

But the Humane Society International (HSI), an animal protection organisation, gave the government’s plan a cautious welcome.

Emily McIvor, its animal research policy director, said: “The Plan itself recognises the desperate impasse in drug development, where 92% of new medicines tested on animals fail in human trials.

“It also highlights barriers posed by underlying conservatism among journal editors and peer review panels that needs to be overcome if progress is to be made.”

Wendy Jarrett, chief executive of Understanding Animal Research, which works to promote understanding about advances stemming from animal testing, said: “We welcome this very clear cross-government statement of the continuing need for well-regulated animal research in the UK.”

The BioIndustry Association (BIA) responded positively to the plan, but its chief executive Steve Bates, said: “Government must ensure that any actions it takes do not negatively impact the ability of British companies to continue to research and develop new products and technologies.”

Despite the Coalition’s 2010 pledge in its Our Programme for Government document, the number of animal experiments has continued to rise steadily.

Latest figures show they rose by 8% in 2012, fuelled by a growth in the use of genetically modified (GM) animals.

About 4.11 million scientific experiments on animals took place in 2012, an increase of 317,200 on the previous year, according to a Home Office report.

Mice were the most frequent animals used, followed by rats, fish and primates such as Old World Monkeys, a group which includes macaques and baboons.