Friday, June 3, 2011

Nerve Stimulation Highly Effective in Battling Tinnitus, Nature Study Reports - UT Dallas News

List of images in Gray's Anatomy: IX. NeurologyImage via WikipediaMicroTransponder, a neuroscience-based medical device company, was founded by UT Dallas Ph.D. candidate Will Rosellini and sponsored by the school’s Institute for Innovation and Entrepreneurship. MicroTransponder is developing a less invasive wireless medical device to stimulate the vagus nerve. The UT Dallas/MicroTransponder team also is studying how best to optimize the paired therapy for tinnitus patients.

Past research has shown that the severity of chronic pain and tinnitus is tied to the degree of plasticity in the brain’s cortex. A previous study showed that repeatedly pairing sensory stimuli with electrical stimulation of a brain structure called nucleus basalis generates powerful and long-lasting changes in cortical organization. Since the vagus nerve is easier to access for clinical use, and is known to trigger the release of molecules in the brain that promote neural changes, follow-up studies were performed on the vagus nerve.

For the VNS study, the research team used a “gap detection model” to document tinnitus in rats that were exposed to loud noise for one hour while under anesthesia. Each of the noise-exposed rats used in this study exhibited a significant impairment in the ability to detect a quiet gap in a tone near their tinnitus frequency, but exhibited no impairment when the gap was placed in a higher or lower tone.
“Previous research showed that a frequency-specific impairment in gap detection is a likely sign that noise-exposed rats experience a mid-frequency tinnitus ‘ringing’ that fills the silent gaps,” Kilgard said. “Though it isn’t possible to evaluate the subjective experience of rats, this gap impairment has been taken as an indicator of tinnitus.”

When the rats were exposed to VNS paired with sounds, the gap impairment was eliminated – indicating that the tinnitus was gone.

Stimulating the Vagus nerve is also being used for  treatment resistant major depression and epilepsy.

http://www.utdallas.edu/news/2011/1/13-8021_Findings-Show-Promise-in-Battle-Against-Tinnitus_article.html

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