Cochlear Damage Affects Neurotransmitter Chemistry in the Central Auditory System

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4237057/

Abstract
Tinnitus, the perception of a monotonous sound not actually present in the environment, affects nearly 20% of the population of the United States. Although there has been great progress in tinnitus research over the past 25 years, the neurochemical basis of tinnitus is still poorly understood. We review current research about the effects of various types of cochlear damage on the neurotransmitter chemistry in the central auditory system and document evidence that different changes in this chemistry can underlie similar behaviorally measured tinnitus symptoms. Most available data have been obtained from rodents following cochlear damage produced by cochlear ablation, intense sound, or ototoxic drugs. Effects on neurotransmitter systems have been measured as changes in neurotransmitter level, synthesis, release, uptake, and receptors. In this review, magnitudes of changes are presented for neurotransmitter-related amino acids, acetylcholine, and serotonin. A variety of effects have been found in these studies that may be related to animal model, survival time, type and/or magnitude of cochlear damage, or methodology. The overall impression from the evidence presented is that any imbalance of neurotransmitter-related chemistry could disrupt auditory processing in such a way as to produce tinnitus.

 

Its always great to see more research being done in this field. It looks like very in depth and well done research!

 

Yes it's interesting to see that cochlear damage can result in the imbalance of neurotransmitters and then eventually cause tinnitus, so theoretically one should be able to reverse this if you knew the exact balance of these neurotransmitters. Anyway, interesting study.

 

@hans01 Interesting article - thanks.

Under Discussion in this link "Tinnitus distress in a younger population is generated by neocortical areas, the distress in elderly patients is generated by the cingulate cortex". There's several other neuro studies that say the same.

https://www.utd.edu/~sxv140030/Published/81.pdf

 

Thanks for the link Greg, not sure why this would be different in younger and older people, when they talk about the distress, they mean the T causing stress or actually the origins of the tinnitus ? thanks

From your links conclusion : "As pathologies such as pain, post-traumatic stress disorder, or depressive disorder show similarities to tinnitus, we speculate that these disease entities may similarly reveal different neural substrates of distress according to the age of onset. This, in turn, could be valuable in constructing calibrated strategies for treatment. We see the current study as a pioneer work along these lines"

The question remains if T makes people depressive or give stress or if the stress and depression is the cause of the Tinnitus. For me it's sure that if I didn't had T I would be less stressed, because mine is really very loud (8 to 9/10 most of the time) and having new tones from time to time is a little too much to handle for me nerves

 

By the way, paper is 3.5 years old.

 

Yes but I never saw it before so thought it could be helpful ...