Upgraded Cochlear Implant Regrows Auditory Nerves

[gwillybj]

Upgraded Cochlear Implant Regrows Auditory Nerves
By Michelle Starr
April 24, 2014


Regenerated auditory nerves after treatment (top) and untreated (below).
(Credit: UNSW Translational Neuroscience Facility)

Researchers at the University of New South Wales have, for the first time, used a cochlear implant to regrow auditory nerves and restore hearing in guinea pigs.

Cochlear implants help the deaf to hear artificially, but a new way to use the existing technology may show promise for one day restoring patients' natural hearing. By applying electrical impulses from a cochlear implant to administer gene therapy, a team of researchers at the University of New South Wales, led by PhD student Jeremy Pinyon and supervised by Professor Gary Housley, has regrown damaged auditory nerves in adult guinea pigs, an animal that has a similar auditory system to humans.

The team modified an existing cochlear implant to administer a type of therapy known as close-field electroporation (CFE) gene therapy. Electroporation involves administering electric pulses to a cell membrane to increase its permeability. This allows new gene constructs to be delivered to the membrane, which encourages growth.

When it comes to the cochlea, a family of proteins called neurotrophins can regenerate auditory nerve endings, but administering treatment — either by drug or viral-based gene therapy — is not safe. However, using the cochlear implant has allowed Professor Housley's team to administer the treatment in a safe, localised fashion.

The implant is modified with an electrode array that delivers the electrical pulses, stimulating an injected complementary DNA gene construct that encourages production of neurotrophins. After a few months, the neurotrophin production dropped, but the team believes that the changes in the auditory nerves may be maintained by the neural activity the implant generated.

"People with cochlear implants do well with understanding speech, but their perception of pitch can be poor, so they often miss out on the joy of music," Professor Housley said. "Ultimately, we hope that after further research, people who depend on cochlear implant devices will be able to enjoy a broader dynamic and tonal range of sound, which is particularly important for our sense of the auditory world around us and for music appreciation."

The team believes the technology may have implications for other kinds of implant therapy, too — deep brain stimulation to treat Parkinson's disease, for example.

"Our work has implications far beyond hearing disorders," co-author Associate Professor Matthias Klugmann, from the UNSW Translational Neuroscience Facility research team, said. "Gene therapy has been suggested as a treatment concept even for devastating neurological conditions and our technology provides a novel platform for safe and efficient gene transfer into tissues as delicate as the brain."

The full research was published today in the journal Science Translational Medicine (http://stm.sciencemag.org/content/6/233/233fs17.abstract).

http://www.cnet.com.au/upgraded-cochlear-implant-regrows-auditory-nerves-339347122.htm

[Buster's Uncle]

THIS is relevant to my interests.

[gwillybj]

Mine, too. My younger stepson had inner ear infections as a toddler and has had two hearing aids since 10 (now 14). I told him about this article and he wants to read it. I think he might really see this technology for human use in his lifetime.

[Buster's Uncle]

I haven't had my ears looked at for a very long time, but I was given to understand then that my ears work fine except for the nerve connection causing the deafness.

[Buster's Uncle]

Ear implant uses electrical impulses to regrow auditory nerves
The Verge
By Arielle Duhaime-Ross on April 23, 2014 02:00 pm






The bionic human is nearly a reality. In recent years, scientists have been able to develop everything from bionic eyes to bionic hands. Yet these machines are still largely dependent on the existing human structures to which they connect. If a person's nerve endings are damaged, for instance, the usefulness of these machines becomes limited. Scientists might soon be able to overcome these obstacles, however, as researchers were able to use an implant to deliver gene therapy to the auditory portion of a guinea pig's ear — a treatment that not only caused the animal's auditory nerves to regrow, but improved the human-machine interface in the process.


The implant sends electrical impulses into surrounding cells


In the study, published today in Science Translational Medicine, researchers used an antibiotic treatment to deafen adult guinea pigs. Then, they introduced recombinant DNA — DNA formed in a lab by combining genetic material from various sources  — into the cochlea, the portion of the guinea pigs' ear that transforms vibrations into sound signals. Once the DNA was in place, they implanted the ear with a modified cochlear implant that was able to send short, directed electrical impulses to the surrounding cells, in addition to enhancing the animals' hearing. These impulses are part of a gene therapy technique called "electroporation" that allowed the recombinant DNA to enter the cochlear cells and produce neurotrophins, proteins that cause auditory nerve endings to regenerate.

"Our gene therapy is an example for a successful treatment of a condition that is not even caused by a genetic defect," says Matthias Klugman, a neuroscientist at the University of New South Wales, in Australia, and a co-author of the study. Thanks to the electrical impulses, the cells close to the implant's electrode were able to manufacture a protein that usually stops being produced after adulthood, Klugman explains. This caused the nerve fibers to grow out to those cells, and hence to the electrodes in the implant. This growth, the researchers say, significantly improved the animals' pitch perception and tonal range.


improved pitch perception and tonal range


Unfortunately, the production of neurotrophins only lasted a few months, so the method needs to be improved before it can go on to human trials. But Gary Housley, a co-author and neuroscientist also at the University of New South Wales, said in an email to The Verge that the implant might one day help people "appreciate music and hear in noisy environments."

Housley also said that the technology could be used to improve other medical bionics applications, such as retinal implants and deep brain stimulation, which is used to treat Parkinson's disease. "Deep brain stimulation uses a small array of electrodes very similar to the cochlear implant array," he said, "so we believe that this could be used to introduce different DNA sequences to very discrete regions of the brain to provide directed gene therapy." These human-machine interfaces also rely on the cells and nerve endings that surround them, so being able to deliver gene therapy in a selective and directed manner could lead to big improvements — and much more powerful bionics.


http://www.theverge.com/2014/4/23/5643244/ear-implant-uses-electrical-impulses-to-regrow-auditory-nerves

[gwillybj]

Biogenetics, Retroviral Engineering, Gene Splicing, Neural Grafting,

[Geo]

Retroviral Engineering,...

BUncle's Private Residences shall remain off-limits to the Genetic Inspectors.

[Yitzi]

Biogenetics, Retroviral Engineering, Gene Splicing, Neural Grafting,

And pushing toward MMI.