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                Simulating Blindness Might Help Improve Hearing

   by Rosanne Skirble

   A new report suggests it might be possible to change the circuitry of
   the brain to better process sound, a finding that could give renewed
   hope to the 350 million people worldwide who suffer from hearing loss.

   [1]Patrick Kanold, an expert on how the brain processes sound and
   co-author of the new study published in [2]Neuron, says a child's brain
   is malleable enough to rewire some circuits that process sensory
   information.
   "We were interested if, at older ages, we can also coax the brain to
   change," he said.
   To try to do that, the University of Maryland biologist and colleagues
   from Johns Hopkins University used a reversible technique to simulate
   blindness by keeping mice with normal vision and normal hearing in
   complete darkness for a week.
   "We want[ed] to know if the deprivation of vision changed the way you
   hear," Kanold said.
   At the end of the week, the mice were put in a sound-proof chamber and
   subjected to a series of one-note tones to test their hearing. The
   scientists then measured the neural response.
   ''"And we found that they hear better and that connections in the brain
   had changed," Kanold said. "It surprised us because during this [adult]
   age, if you would alter the auditory experience of mice, the hearing
   would not change, but we found if you deprive them of vision, the
   hearing did change."
   The mice developed more neural connections, and could better
   discriminate among pitches and hear softer sounds.
   "These tones could not be distinguished by mice that were raised
   normally, but could be distinguished by animals that were sitting in
   the dark," Kanold said. "So they got much better distinguishing these
   very close by frequencies."
   Kanold says while the rodents' sharper hearing reverted back to normal
   within a few weeks, the experiment detailed in the journal Neuron
   demonstrated the adult brain may be less hard-wired than previously
   thought. By temporarily preventing vision, Kanold says, it may be
   possible to change the brain circuitry to better process sound.
   The next step for the researchers is work on making those changes in
   hearing last longer. Kanold says what they find could lead to
   treatments for people.
   "This approach potentially might be useful for humans, where the
   peripheral hearing is fine, but where the central processing of sound
   stimuli is altered," he said.
   That could give renewed hope to the estimated 360 million people who
   suffer from disabling hearing loss.
     __________________________________________________________________

   [3]http://www.voanews.com/content/simulating-blindness-might-help-impro
   ve-hearing/1845240.html

References

   1. http://biology.umd.edu/faculty/patrickkanold
   2. https://www.cell.com/neuron/abstract/S0896-6273%2813%2901091-X
   3. http://www.voanews.com/content/simulating-blindness-might-help-improve-hearing/1845240.html