Mouse model of tinnitus - 'neuroinflammation'

[Marco]

Edited abstract :

Although recent studies indicate that hearing loss causes neuroinflammation in the auditory pathway, the mechanisms underlying hearing loss–related pathologies are still poorly understood. We examined neuroinflammation in the auditory cortex following noise-induced hearing loss (NIHL) and its role in tinnitus in rodent models.

Our results indicate that NIHL is associated with elevated expression of proinflammatory cytokines and microglial activation—two defining features of neuroinflammatory responses—in the primary auditory cortex (AI).

Genetic knockout of tumor necrosis factor alpha (TNF-α) or pharmacologically blocking TNF-α expression prevented neuroinflammation and ameliorated the behavioral phenotype associated with tinnitus in mice with NIHL. Conversely, infusion of TNF-α into AI resulted in behavioral signs of tinnitus in both wild-type and TNF-α knockout mice with normal hearing.

These results implicate neuroinflammation as a therapeutic target for treating tinnitus and other hearing loss–related disorders.

https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3000307

 

[Jonathan Edwards]

How do they know the mice have tinnitus I wonder?

To find out if a person has tinnitus you have to ask them in a language they understand.

 

[Sly Saint]

How do they know the mice have tinnitus I wonder?

To find out if a person has tinnitus you have to ask them in a language they understand.

 

[Mithriel]

Well they don't ask patients so why would they worry about asking mice?

 

[Forbin]

I think they attempt to induce tinnitus by exposing the mouse to a loud sound. Subsequently, they use a "gap detection test," where another sound is played which has a "gap of silence" in it. The mice have been trained to react to the gap of silence in some way (e.g. they stop licking water). Normal mice will react to the gap of silence as they were trained, but mice with tinnitus will not - presumably because the gap of silence is "filled" by the sound of their tinnitus.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4478067/

 

[Jonathan Edwards]

Normal mice will react to the gap of silence as they were trained, but mice with tinnitus will not - presumably because the gap of silence is "filled" by the sound of their tinnitus.

Tinnitus does not stop you noticing gaps in other sounds - I know because I have tinnitus. It seems more likely the mice do not notice the gap because they cannot hear well enough!

 

[Forbin]

Tinnitus does not stop you noticing gaps in other sounds - I know because I have tinnitus. It seems more likely the mice do not notice the gap because they cannot hear well enough!

They may not have been trained to react to the absence of the sound created by the gap, but rather to react to total silence - something they couldn't experience with tinnitus. I did wonder, though, how they could be certain that the mice weren't simply deaf.

 

[Marco]

Tinnitus does not stop you noticing gaps in other sounds - I know because I have tinnitus. It seems more likely the mice do not notice the gap because they cannot hear well enough!

There's a full description in the methods section - Behavioral test of tinnitus with an acoustic startle reflex-based gap detection paradigm