Rewired Brain Leads to Compromised Hearing
Scientists at Georgia State University have found that the ability to hear is lessened when, as a result of traumatic brain injury, a region of the brain responsible for processing sounds receives both visual and auditory input. The findings may help people who are deaf, blind, or have suffered brain injuries preserve their visual and auditory functions.
In a study published in the Journal of Neuroscience (doi: 10.1523/JNEUROSCI.6524-11.2012), researchers explored how the brain's ability to change—neuroplasticity—affected its ability to process sounds when both visual and auditory information are sent to the auditory thalamus. This brain region is responsible for carrying sound information to the auditory cortex, where sound is processed in detail.
When a person or animal loses input from one of the senses—such as hearing—the brain region that processes that information does not become inactive, but instead gets rewired with input from other sensory systems. In the case of this study, brain injuries suffered early in life resulted in visual inputs into the auditory thalamus, which altered how the auditory cortex processes sounds. Scientists also discovered reduced sensitivity and slower responses to sound by neurons in the auditory cortex, and that neurons in the auditory cortex were less sharply tuned to different frequencies of sound.
"Generally, individual neurons will be pretty sensitive to one sound frequency that we call their 'best frequency,'" said Sarah L. Pallas, professor of neuroscience. "We found that they would respond to a broader range of frequencies after the rewiring with visual inputs."
Top Job in Health Care
Dental hygienist, audiolo-gist, and occupational therapist ranked as the top three health care jobs in the nation, according to a new report by CareerCast.com, with audiologists earning a median salary of $67,137 and experiencing much faster than average job growth. Other highly rated health care jobs include physical therapist, optometrist, pharmacist, physician's assistant, chiropractor, general practice physician, registered nurse, speech-language pathologist, and psychiatrist.Wage and salary employment in the health care industry is projected to increase 27% through 2014, compared with 14% for all industries combined, says the report. According to the Bureau of Labor Statistics, the health care and social assistance industry is projected to contribute about 28% of all new jobs created in the U.S. economy from 2010 to 2020.
This industry—which includes public and private hospitals, nursing and residential care facilities, and individual and family services—is expected to grow by 33%, or 5.7 million new jobs. An aging population and longer life expectancies, as well as new treatments and technologies, will drive employment growth. Visit CareerCast HealthCare Network.
Analgesics Increase Hearing Loss Risk in Women
According to a study by researchers at Brigham and Women's Hospital, women ages 31–48 who took ibuprofen or acetaminophen two or more days per week had an increased risk of hearing loss. The link tended to be greater in women younger than 50, especially for those who took ibuprofen six or more days per week. There was no association between aspirin use and hearing loss.
In the study, published in the Sept. 15 American Journal of Epidemiology (doi: 10.1093/aje/kws146), researchers prospectively examined the relationship between frequency of aspirin, ibuprofen, and acetaminophen use and risk of hearing loss among women. They studied data from 62,261 women, then followed them from 1995 to 2009, many past the age of 50. Of the participants, 10,012 self-reported hearing loss.
Compared with women who used ibuprofen less than once per week, those who used ibuprofen two to three days per week had a 13% increased risk for hearing loss, and women who used the medication four to five days per week had a 21% increased risk. For those who used ibuprofen six or more days per week, the increased risk was 24%.
Compared with women who used acetaminophen less than once per week, women who used acetaminophen two to three days per week had an 11% increased risk for hearing loss, and women taking the medicine four to five days per week had a 21% increased risk.