AUT00063 & Auditory Nerve Damage

Aaron123

Member
Author
Aug 6, 2015
843
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Cause of Tinnitus
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Interesting paper (https://www.nature.com/articles/s41598-017-17406-x) using AUT00063 in a model of auditory nerve damage though it is a bit weird that they refer to AUT00063 as something new. Unfortunately, the paper concludes on a cautionary note (emphasis added): "Chronic application of exogenous compounds that decrease excitability or improve stimulus coding in the short-term can themselves engage compensatory processes that would render potential therapies ineffective in the long-term. In this regard, approaches that reprogram neural set points of excitability through gene therapy rather than pharmacological approaches that continuously push against the tide of hyperexcitability may also prove useful." Thus, as it does with many drugs (e.g., Xanax) the body may adapt to AUT00063 in ways that would make it less effective over time.

Anyway, here's the title and abstract:

Pharmacological modulation of Kv3.1 mitigates auditory midbrain temporal processing deficits following auditory nerve damage

Abstract

Higher stages of central auditory processing compensate for a loss of cochlear nerve synapses by increasing the gain on remaining afferent inputs, thereby restoring firing rate codes for rudimentary sound features. The benefits of this compensatory plasticity are limited, as the recovery of precise temporal coding is comparatively modest. We reasoned that persistent temporal coding deficits could be ameliorated through modulation of voltage-gated potassium (Kv) channels that regulate temporal firing patterns. Here, we characterize AUT00063, a pharmacological compound that modulates Kv3.1, a high-threshold channel expressed in fast-spiking neurons throughout the central auditory pathway. Patch clamp recordings from auditory brainstem neurons and in silico modeling revealed that application of AUT00063 reduced action potential timing variability and improved temporal coding precision. Systemic injections of AUT00063 in vivo improved auditory synchronization and supported more accurate decoding of temporal sound features in the inferior colliculus and auditory cortex in adult mice with a near-complete loss of auditory nerve afferent synapses in the contralateral ear. These findings suggest modulating Kv3.1 in central neurons could be a promising therapeutic approach to mitigate temporal processing deficits that commonly accompany aging, tinnitus, ototoxic drug exposure or noise damage.
 
Does this mean they possibly can lessen tinnitus or that it won't be getting worse? My English is not that good. Interesting that a lot of research is going on.
 
I found this abstract today. I thought it was pertinent to post it in this thread because it is related. (almost the same teams, same compound, but different abstracts).

Increased Spontaneous Firing Rates in Auditory Midbrain Following Noise Exposure Are Specifically Abolished by a Kv3 Channel Modulator

Highlights
Spontaneous activity in mouse inferior colliculus is elevated after noise exposure
AUT00063, a novel Kv3 channel modulator, normalises this midbrain pathology
No effect of AUT00063 on IC spontaneous activity without noise exposure
No effect of AUT00063 on IC tone-evoked response thresholds or frequency tuning
Abstract
Noise exposure has been shown to produce long-lasting increases in spontaneous activity in central auditory structures in animal models, and similar pathologies are thought to contribute to clinical phenomena such as hyperacusis or tinnitus in humans. Here we demonstrate that multi-unit spontaneous neuronal activity in the inferior colliculus (IC) of mice is significantly elevated four weeks following noise exposure at recording sites with frequency tuning within or near the noise exposure band, and this selective central auditory pathology can be normalised through administration of a novel compound that modulates activity of Kv3 voltage-gated ion channels. The compound had no statistically significant effect on IC spontaneous activity without noise exposure, nor on thresholds or frequency tuning of tone-evoked responses either with or without noise exposure. Administration of the compound produced some reduction in the magnitude of evoked responses to a broadband noise, but unlike effects on spontaneous rates, these effects on evoked responses were not specific to recording sites with frequency tuning within the noise exposure band. Thus, the results suggest that modulators of Kv3 channels can selectively counteract increases in spontaneous activity in the auditory midbrain associated with noise exposure.

Keywords
  • inferior colliculus;
  • noise exposure;
  • acoustic trauma;
  • potassium channels;
  • spontaneous activity;
  • AUT00063
Source: https://www.sciencedirect.com/science/article/pii/S0378595517302678
 

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