Category: Hearing Loss

Children with permanent hearing impairment who received hearing screening as newborns had better general and language developmental outcomes and quality of life at ages 3 to 5 years compared to newborns who received hearing screening through behavioral testing, according to a study in the October 20 issue of JAMA.

Permanent childhood hearing impairment is a serious, relatively common condition. Auditory input is essential for development and social functioning, so early awareness of a child's hearing ability is important in creating opportunities for early amplification when necessary, according to background information in the article. "Until some years ago, distraction hearing screening (behavioral testing) was used for hearing screening around the age of 9 months. Newborn hearing screening (within 2 weeks of birth) was introduced in many developed countries because it was thought that the earlier permanent childhood hearing impairment was diagnosed, the less developmentally disadvantaged children would become. However, to date no strong evidence exists for universal implementation of newborn hearing screening," the authors write.

Anna M. H. Korver, M.D., Ph.D., of Leiden University Medical Center, Leiden, the Netherlands, and colleagues studied the association between developmental outcomes and newborn hearing screening compared with distraction hearing screening in 3- to 5-year-old children with permanent childhood hearing impairment. Between 2002 and 2006, 65 regions in the Netherlands replaced distraction hearing screening with newborn hearing screening. The type of hearing screening offered was based on availability at the place and date of birth and was independent of developmental prognoses of individual children. All children born in the Netherlands between 2003 and 2005 were included. At the age of 3 to 5 years, all children with permanent childhood hearing impairment were identified. Evaluation ended December 2009.

During the study period, 335,560 children were born in a region where newborn hearing screening was offered and 234,826 in a region where distraction hearing screening was offered. At follow-up, 263 children in a newborn hearing screening region had been diagnosed with permanent childhood hearing impairment (0.78 per 1,000 children) and 171 children in a distraction hearing screening region (0.73 per 1,000 children).

Three hundred one children (69.4 percent) participated in analysis of general performance measures. In this analysis, the 2 groups (newborn hearing screening, n = 183; distraction hearing screening, n = 118) were comparable in degree of hearing impairment and type of education. Analysis of extensive developmental outcomes included 80 children born in newborn hearing screening regions and 70 in distraction hearing screening regions. The analysis showed that overall, children in newborn hearing screening regions had higher developmental outcome scores compared with children in distraction hearing screening regions, including on measures of social development, gross motor development and quality of life.

"The results of [this] study add evidence to the presumed importance and effectiveness of the implementation of universal newborn hearing screening programs. Because this study was performed nationwide, among all children born in the Netherlands in 3 subsequent years, we believe our results can be generalized to other countries with universal hearing screening programs, but the feasibility and effectiveness of newborn hearing screening programs in other countries remain to be studied," the authors write.

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Journal Reference:

1. Anna M. H. Korver; Saskia Konings; Friedo W. Dekker; Mieke Beers; Capi C. Wever; Johan H. M. Frijns; Anne M. Oudesluys-Murphy; for the DECIBEL Collaborative Study Group. Newborn Hearing Screening vs Later Hearing Screening and Developmental Outcomes in Children With Permanent Childhood Hearing Impairment. JAMA, 2010; 304 (15): 1701-1708 DOI: 10.1001/jama.2010.1501

Researchers at the University of Minnesota Medical School have gained insight into how different types of age-related hearing loss may occur in humans. The discovery could eventually help physicians develop drugs to combat progressive hearing loss. Their paper is published on October 14 in the open-access journal PLoS Genetics.

James Ervasti, Ph.D., and colleague Ben Perrin, Ph.D., studied how two very closely related genes contribute to hearing function in mice. Mutations in the same genes are associated with deafness in humans. The duo discovered two key cellular processes that are required to maintain auditory function.

The genes encode proteins called β-actin and γ-actin. In humans, deafness-causing mutations have been linked to both proteins. β- and γ-actin comprise the primary structural elements of stereocilia (hair-like fibers in the ear), which convert mechanical sound energy into the nerve signals that allow humans to hear.

The two proteins are 99 percent identical; however, their slight differences have been exactly conserved through evolution from birds to mammals, suggesting that each protein may have important and distinct functions. Ervasti and Perrin tested the idea that two closely linked proteins have separate, but important, roles in hearing by knocking out each gene in mouse auditory hair cells.

They found that β-actin and γ-actin do have different maintenance functions that together keep the hair-like fibers — that allow mice to hear — healthy. Both knockout mice had normal hearing at young ages, but developed specific types of progressive hearing loss and stereocilia pathology that differed depending on which protein was lost.

"These separate maintenance pathways are likely important for maintaining auditory function during aging and may contribute to future understanding of common forms of age-related hearing loss in humans," Perrin said.

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Journal Reference:

1. Bruce L. Tempel, Benjamin J. Perrin, Kevin J. Sonnemann, James M. Ervasti. β-Actin and γ-Actin Are Each Dispensable for Auditory Hair Cell Development But Required for Stereocilia Maintenance. PLoS Genetics, 2010; 6 (10): e1001158 DOI: 10.1371/journal.pgen.1001158

Deaf or blind people often report enhanced abilities in their remaining senses, but up until now, no one has explained how and why that could be. Researchers at The University of Western Ontario, led by Stephen Lomber of The Centre for Brain and Mind have discovered there is a causal link between enhanced visual abilities and reorganization of the part of the brain that usually handles auditory input in congenitally deaf cats.

The findings, published online in Nature Neuroscience, provide insight into the plasticity that may occur in the brains of deaf people.

Cats are the only animal besides humans that can be born deaf. Using congenitally deaf cats and hearing cats, Lomber and his team showed that only two specific visual abilities are enhanced in the deaf: visual localization in the peripheral field and visual motion detection. They found the part of the auditory cortex that would normally pick up peripheral sound enhanced peripheral vision, leading the researchers to conclude the function stays the same but switches from auditory to visual.

"The brain is very efficient, and doesn't let unused space go to waste," says Lomber, an associate professor in the Department of Physiology and Pharmacology at the Schulich School of Medicine & Dentistry, and Department of Psychology in the Faculty of Social Science. "The brain wants to compensate for the lost sense with enhancements that are beneficial. For example, if you're deaf, you would benefit by seeing a car coming far off in your peripheral vision, because you can't hear that car approaching from the side; the same with being able to more accurately detect how fast something is moving."

Lomber and his team are trying to discover how a deaf brain differs from a hearing brain to better understand how the brain handles cochlear implants. If the brain has rewired itself to compensate for the loss of hearing, what happens when hearing is restored? "The analogy I use is, if you weren't using your cottage and lent it to a friend. That friend gets comfortable, maybe rearranges the furniture, and settles in. They may not want to leave just because you've come back," explains Lomber.

He also plans to conduct research to see if these changes in the brain also happen to those who could hear at one time, or if auditory experience prevents the changes from occurring.

The other authors on the paper are Andrej Kral of Medical University Hannover in Germany and Alex Meredith of Virginia Commonwealth University. The research was funded by the Canadian Institutes of Health Research.

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Journal Reference:

1. Stephen G Lomber, M Alex Meredith, Andrej Kral. Cross-modal plasticity in specific auditory cortices underlies visual compensations in the deaf. Nature Neuroscience, 2010; DOI: 10.1038/nn.2653

New research shows that an intravenous (IV) treatment may cut a person's risk of dying from bacterial meningitis. The research is published in the September 29, 2010, online issue of Neurology®, the medical journal of the American Academy of Neurology. The treatment is called dexamethasone.

"Using this treatment in people infected with meningitis has been under debate because in a few large studies it was shown to be ineffective," said study author Diederik van de Beek, MD, PhD, with the Academic Medical Center, University of Amsterdam in the Netherlands and a member of the American Academy of Neurology. "Our results provide valuable evidence suggesting that dexamethasone is effective in adult cases of bacterial meningitis and should continue to be used."

Bacterial meningitis is a condition that causes membranes in the brain and spinal cord to become inflamed. The disease can be deadly, or result in hearing loss, brain damage and learning disabilities. Pneumococcal meningitis is the most common and severe form of bacterial meningitis. It is estimated that about 25 to 30 percent of people die from the disease.

For the study, researchers evaluated 357 Dutch people age 16 or older with pneumococcal meningitis between 2006 and 2009. Of those, 84 percent were given dexamethasone through an IV with or before the first dose of antibiotics. The results were compared to an earlier study of 352 people treated for bacterial meningitis in 1998-2002, before Netherlands guidelines recommended using dexamethasone. In that study, only three percent of the people were given dexamethasone.

In both studies, participants were assessed on a rating scale of one to five. A score of one was given for death, two for coma, three for severe disability, four for moderate disability and five for mild or no disability. In the later study, 39 percent had an "unfavorable outcome," or a score of four or lower on the scale, compared to 50 percent in the earlier study group.

The study found that the rate of death for those who were given dexamethasone was 10 percent lower than in those in early study group. The rates of hearing loss were also nearly 10 percent lower for those in the later study group.

Symptoms of bacterial meningitis are neck stiffness, fever and an altered mental state. These are also symptoms of viral meningitis, which is more common, much less serious and was not the focus of this study. Bacterial meningitis is a medical emergency and is diagnosed by culturing bacteria from the spinal fluid or by observing changes in the spinal fluid which indicate the presence of bacteria. Bacterial meningitis must always be treated with antibiotics in addition to medications like dexamethasone, which is a medication of the glucocorticosteroid class of drugs and may be used for bacterial meningitis.

The study was supported by the Netherlands Organization for Health Research and Development and the Academic Medical Center, University of Amsterdam.

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Journal Reference:

1. E. Soemirien Kasanmoentalib, Matthijs C. Brouwer, Arie van der Ende, and Diederik van de Beek. Hydrocephalus in adults with community-acquired bacterial meningitis. Neurology, 2010; 75: 918-923 [link]

Playing white noise in class can help inattentive children learn. Researchers writing in BioMed Central's open access journal Behavioral and Brain Functions tested the effect of the meaningless random noise on a group of 51 schoolchildren, finding that although it hindered the ability of those who normally pay attention, it improved the memory of those that had difficulties in paying attention.

Göran Söderlund from Stockholm University, Sweden, worked with a team of researchers to carry out the experiments at a secondary school in Norway. He said, "There was significant improvement in performance for the children rated as inattentive by their teachers, and a significant decline in performance for those rated as attentive as noise levels were increased. This finding could have practical applications offering non-invasive and non-pharmacological help to improve school results in children with attentional problems."

The children were challenged to remember as many items as possible from a list read out either in the presence or absence of white noise. The researchers speculate that a phenomenon called 'stochastic resonance' may explain the improved performance of inattentive pupils seen in the test. According to Söderlund, "When a weak signal is presented below the hearing threshold it becomes detectable when random or white noise is added to the signal. Our study is the first to link noise and stochastic resonance to both higher cognitive functions and attention."

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Journal Reference:

1. Goran B. W. Soderlund, Sverker Sikstrom, Jan M. Loftesnes and Edmund J. Sonuga-Barke. The effects of background white noise on memory performance in inattentive school children. Behavioral and Brain Functions, (in press) [link]

A study carried out by Spanish researchers has shown that the presence of chemical contaminants can interact with noise and modify, for good or for bad, the way in which work-related "deafness" — which is increasingly common among young people — manifests itself. Noise-related hearing loss is the most common occupational disease in Europe.

"Workers exposed to noise in the presence of metalworking fluids exhibit a delay in hearing alteration in comparison with those exposed only to noise at the same intensity. However, those exposed to noise in the presence of welding fumes experience increased hearing alteration," says Juan Carlos Conte, lead author of the study and a researcher at the University of Zaragoza.

In the study, published in Anales del Sistema Sanitario de Navarra, the team analysed the way in which various physical and chemical contaminants interact, and the impact this had on hearing alteration in 558 metal workers

"A problem we detected with respect to welding fumes in the presence of noise was that the protection used is effective for reducing the intensity of noise, but not for reducing the effects of the chemical contaminant," Conte explains.

Cellulose masks or others made of similar compounds have little effect in this case, since their capacity to filter particles (such as charcoal) has no effect on toxic gas molecules (such as carbon monoxide).

However, in noisy atmospheres with metalworking fluids, people have the advantage of being able to use masks as respiratory protection, although the ear protection must be used in the same way to ensure that a person is comprehensively protected from noise.

The researchers point to other factors in work-related hearing loss. For example, tobacco contributes to the acquisition of initial acoustic trauma, while exposure to noise outside the work environment also impacts on advanced acoustic injury.

Too much noise at work

The European Agency for Safety and Health at Work (EU-OSHA, 2006) recognises that noise-related hearing loss is the most common professional disease seen in Europe, and suggests greater focus should be placed on combined risk factors in workers exposed to high noise levels and chemical compounds.

Recent studies carried out in the United States (Agrawall et al. 2009) and New Zealand (Thorne et al. 2008) show that noise-related hearing loss is one of the most widely spread professional illnesses in those countries. They concluded that the classic methods used to control this problem have not had the expected results, and detected ever-increasing prevalence, particularly in young people.

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Journal Reference:

1. J.C. Conte, A. I. Domínguez, A. I. García Felipe, E. Rubio, A. Pérez Prados. Cox regression model of hearing loss in workers exposed to noise and metalworking fluids or welding fumes. Anales del Sistema Sanitario de Navarra, 2010; 33 (1)

Scientists long have recognized that many perceptual skills important for language comprehension and reading can be enhanced through practice. Now research from Northwestern University suggests a new way of training that could reduce by at least half the effort previously thought necessary to make learning gains.

The research also may be the first behavioral demonstration of metaplasticity — the idea that experiences that on their own do not generate learning can influence how effective later experiences are at generating learning.

"Prior to our work much of the research into perceptual learning could be summed up as 'no pain, no gain,'" says Beverly Wright, first author of a study in the Sept. 22 Journal of Neuroscience and communication sciences and disorders professor at Northwestern. "Our work suggests that you can have the same gain in learning with substantially less pain."

The findings could lead to less effortful therapies for children who suffer from language learning impairments involving perceptual skills. And they hold potential for members of the general population with an interest in enhancing perceptual abilities — for musicians seeking to sharpen their sensitivity to sound, people studying a second language or physicians learning to tell the difference between regular and irregular heartbeats.

Previous research showed that individuals become better at many perceptual tasks by performing them again and again, typically making the training tedious and long in length. It also showed that mere exposure to the perceptual stimuli used during practice on these tasks does not generate learning.

But the Northwestern researchers found that robust learning occurred when they combined periods of practice that alone were too brief to cause learning with periods of mere exposure to perceptual stimuli. "To our surprise, we found that two 'wrongs' actually can make a right when it comes to perceptual learning," says Wright.

What's more, they found that the combination led to perceptual learning gains that were equal to the learning gains made by participants who performed twice as much continuous task training (training which by nature of its repetition and length often is onerous).

"It's as though once you get your system revved up by practicing a particular skill, the brain acts as though you are still engaged in the task when you are not and learning still takes place," says Wright, who teaches in Northwestern's School of Communication.

Wright and Northwestern researchers Andrew Sabin, Yuxuan Zhang, Nicole Marrone and Matthew Fitzgerald worked with four groups of adult participants aged 18 to 30 years with normal hearing and no previous experience with psychoacoustic tasks. Their goal was to improve participants' ability to discriminate between the pitches of different tones.

The researchers initially determined the smallest difference in pitch that participants could discriminate from a 1,000 Hertz standard tone. They then divided the participants into four groups, each of which went through a different training regimen.

Participants in one group were trained for 20 minutes per day for a week on the pitch-discrimination task. Over and over again, they were asked to tell the difference between the 1,000 Hertz tone and a lower tone but showed no improvement.

Of greatest importance for the study, participants in a second group showed significant learning gains when the same amount of target task training (20 minutes) was combined with 20 minutes of work on an unrelated puzzle while repeatedly presenting a 1,000 Hertz tone through headphones.

Impressively, the learning of the second group also was comparable to that of a third group that for a week practiced the pitch-discrimination target task for 40 minutes per day.

A fourth group of participants repeatedly exposed to a 1,000 Hertz tone for 40 minutes per day while performing an unrelated task showed no learning gains.

Further experiments revealed that the order of presentation — whether the 20 minutes of target task training occurred before or after the 20 minutes of the related task — did not affect learning. Each scenario yielded equal pitch discrimination learning gains.

In addition, the researchers discovered that the effectiveness of the combination of the target task training and of the unrelated training plus stimuli presentation began declining if the two tasks were separated by more than 15 minutes. Pitch discrimination learning — or evidence of metaplasticity — disappeared completely if the sessions were separated by four hours.

The research is supported by the National Institute on Deafness and Other Communication Disorders-National Institutes of Health.

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Journal Reference:

1. Beverly A. Wright, Andrew T. Sabin, Yuxuan Zhang, Nicole Marrone, and Matthew B. Fitzgerald. Enhancing Perceptual Learning by Combining Practice with Additional Sensory Stimulation. Journal of Neuroscience, 2010; 30: 12868-12877 DOI: 10.1523/JNEUROSCI.0487-10.2010

"Yeah, I'm on my way home." "That's funny." "Uh-huh." "What? No! I thought you were — " "Oh, ok." Listening to someone talk on a cell phone is very annoying. A new study published in Psychological Science, a journal of the Association for Psychological Science, finds out why: Hearing just one side of a conversation is much more distracting than hearing both sides and reduces our attention in other tasks.

Lauren Emberson, a psychology Ph.D. candidate at Cornell University, came up with the idea for the study when she was taking the bus as an undergraduate student at the University of British Columbia in Vancouver, Canada. "I was commuting for 45 minutes by bus every day and I really felt like I couldn't do anything else when someone was on a cell phone," she says. "I couldn't read. I couldn't even listen to my music. I was just so distracted, and I started to wonder about why that could be."

For the experiment, Emberson recorded two pairs of female college roommates as they had a cell phone conversation. She recorded each conversation both as a dialogue, in which both women could be heard by a listener, and as a "halfalogue" in which only one side of the conversation could be heard, the same as overhearing a cell-phone conversation. She also recorded each woman recapping the conversation in a monologue. Then she played the recordings at volunteers as they did various tasks on the computer that require attention, such as tracking a moving dot using a computer mouse.

Sure enough, volunteers were much worse at the concentration tasks when they could only hear half of the conversation. Emberson thinks this is because our brains more or less ignore predictable things, while paying more attention to things that are unpredictable. When both sides of the conversation are audible, it flows predictably, but a cell phone conversation is quite unpredictable. Emberson conducted the study with Gary Lupyan of the University of Wisconsin-Madison, Michael Goldstein of Cornell University, and Michael Spivey of the University of California-Merced.

"It's definitely changed my own etiquette," says Emberson. "I'm a lot more sensitive about talking on the phone in public. It has a really profound effect on the cognition of the people around you, and it's not because they're eavesdropping or they're bad people. Their cognitive mechanism basically means that they're forced to listen."

The article, "Overheard Cell-Phone Conversations: When Less Speech Is More Distracting" was recently published in the journal Psychological Science.

New research from University of Minnesota hearing scientists shows that fewer than 20 percent of teenagers in the United States have a hearing loss as a result of exposure to loud sounds, thus offering a different analysis of data reported in the Journal of the American Medical Association (JAMA) in August.

The U of M's research, forthcoming in the Journal of Speech, Language, and Hearing Research, points out that the small hearing losses that audiologist are trying to identify with conventional hearing tests are subject to measurement error and that as many as 10 percent or more of children are falsely identified as having a noise induced hearing loss using these methods.

"Most media have emphasized the link between exposure to loud sounds and hearing loss when referring to the JAMA study," says Bert Schlauch, professor in the university's Department of Speech-Language-Hearing Sciences. "However, many of the findings of the JAMA study are not consistent with hearing loss caused by exposure to loud sounds." These conclusions were drawn from an ongoing study of the hearing of the University of Minnesota Marching Band and a forthcoming paper in the Journal of Speech, Language and Hearing Research authored by Schlauch and Edward Carney.

The U of M researchers measured the hearing of members of the university's marching band and found about 15 percent had hearing loss. Researchers followed the band members over the period of a year. When the results of multiple hearing tests were averaged, more than half of the apparent noise induced hearing losses disappeared, a finding consistent with measurement error.

The JAMA study examined two sets of data collected as part of a national study of health and nutrition. Schlauch and Carney examined the older data set that was included in the JAMA study. A highly cited study, published in the journal Pediatrics, examined the older data set and reported an estimated prevalence of 14.9 percent of 12 to 19-year-old children who had hearing loss consistent with noise exposure.

Schlauch and Carney report, based on computer simulations modeling the statistical properties of hearing tests, that as much as 10 percent of the 14.9 percent figure is consistent with false positive responses. In other words, people with normal hearing can produce spurious responses during a hearing test that look like a mild hearing loss, a result consistent with measurement error.

"Our findings do not mean that people should not be concerned about exposure to loud sounds, such as those from personal stereo devices, live music concerts or gun fire," Schlauch says. "The damage may build up over time and not appear until a person is older. For all sounds, the risk increases the more intense the sound and the longer the exposure, particularly from sustained or continuous sounds."

The paper, "Are False Positive Rates Leading to an Overestimation of Noise-Induced Hearing Loss," forthcoming in the Journal of Speech, Language, and Hearing Research, was co-authored by Bert Schlauch and Edward Carney. Ongoing work is a collaborative effort with Su-Hyun Jin, University of Texas at Austin, and Bert Schlauch, Peggy Nelson and Edward Carney in the Department of Speech-Language-Hearing Sciences, College of Liberal Arts, University of Minnesota.

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Journal References:

1. R. S. Schlauch, E. Carney. Are False Positive Rates Leading to an Overestimation of Noise-Induced Hearing Loss?Journal of Speech, Language, and Hearing Research, 2010; DOI: 10.1044/1092-4388(2010/09-0132)
2. J. Shargorodsky, S. G. Curhan, G. C. Curhan, R. Eavey. Change in Prevalence of Hearing Loss in US Adolescents. JAMA: The Journal of the American Medical Association, 2010; 304 (7): 772 DOI: 10.1001/jama.2010.1124

Researchers have tracked a cell-to-cell signaling pathway that designates the future location of the ear's sensory organs in embryonic mice. The scientists succeeded in activating this signal more widely across the embryonic tissue that becomes the inner ear. Patches of sensory structures began growing in spots where they don't normally appear.

The structures contained tufted cells, called hair cells, which respond to sound waves and other sensations, and additional nerve cells that amplify or code sounds for the brain to interpret.

The results suggest an avenue for further investigation in restoring hearing loss from nerve damage.

The findings are reported in the early online edition of Proceedings of the National Academy of Sciences by researchers Byron H. Hartman, Thomas Reh, and Olivia Bermingham- McDonogh of the Department of Biological Structure at the University of Washington (UW) in Seattle. All three are members of the UW Institute for Stem Cells and Regenerative Medicine. The senior author, Bermingham-McDonogh, is also an affiliate of the UW Virginia Merrill Bloedel Hearing Research Center.

"As the population ages," said Bermingham-McDonogh, "there's a great interest in discovering how to regenerate the inner ear sensory cells that we need for our hearing and balance. Both of these falter as we get older — we get hard of hearing and unsteady on our feet — due to accumulated destruction of the sensory cells in the inner ear."

The goal of their research is to develop ways to restore inner ear sensory hair cells in people who have lost them due to age, excessive noise or other toxic damage. The hair cells do not spontaneously recover after they are lost, and adult stem cells have not been found in the mammalian inner ear. In order to devise a way to restart hair cell formation in the adult ear, Bermingham-McDonogh's group is studying how hair cells are made in the first place during ear development.

The first stage in the normal development of hair cells is called prosensory specification. In the growing embryo, regions of the ear-forming tissue are selected to become the inner ear organs that detect sound and allow for our sense of balance. This action is similar to digging the foundation of a building. All the subsequent, complex steps in the construction of the building require a solid foundation.

Byron Hartman, a postdoctoral fellow in the Bermingham-McDonogh lab, found that a signaling system called the Notch pathway is important in laying the foundation for the inner ear sensory hair cells and their associated supporting cells. The researchers were able to activate the Notch pathway in regions of the inner ear that would normally never make hair cells and convert these regions to patches of new sensory tissue. In other words, they could encourage the formation of new building foundations throughout the inner ear. Once these new sensory patches were made, new hair cells and support cells were properly produced within them. So by starting the ball rolling with the Notch signal, the researchers observed that the rest of the developmental processes followed along correctly.

Notch proteins straddle the inside and outside of the cell membrane. They collect information at the cell surface and report to the cell's operations center, the nucleus. Embryologists and cancer researchers have been studying the Notch pathway for many years. More recently scientists in the regenerative medicine field have begun taking advantage of this key regulatory signal to restart developmental processes in adults.

"The Notch signaling for prosensory specification does not appear to be active in the mature inner ear," the UW researchers noted, "and this could explain their lack of ability to regenerate new hair cells." They are now studying ways of manipulating the Notch pathway in the adult inner ear to see if this will stimulate hair cell regeneration in the hearing and balance organs.

If ways could be found to safely re-start particular Notch signals in adults, therapies might be designed to regenerate specific tissues, like nerves, and thereby repair damage and restore lost function, like hearing. Perhaps this knowledge, they noted, may lead to ideas on how to re-create this earlier state in the mature adult ear to stimulate re-growth of the cells critical to hearing.

The research for "Notch signaling specifies processor domains via lateral induction of the developing mammal inner ear" was supported by a National Research Service Award and grants from the National Institute on Deafness and Other Communication and National Eye Institute, both part of the National Institutes of Health, and assistance from the Lynn and Mike Garvey Cell Imaging Laboratory at the UW Institute for Stem Cell and Regenerative Medicine Research.

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Journal Reference:

1. Wei Pan, Ying Jin, Ben Stanger, and Amy E. Kiernan. Notch signaling specifies processor domains via lateral induction of the developing mammal inner ear. Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.1003089107