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Comment by CommanderData | Hacker News Reader

We are a long way from a cure.

Hearing is complicated, this is a repost and it's believed many components need to be fixed in order to hear again. A drug (FX-322) was pulled recently after reaching stage 2 clinical trials and had good evidence of regenerating hair cells via progenitors in mice and cadaver.

Hair cells are not even considered the first thing to be damaged when one notices hearing loss. It's considered neurons connecting the audiotry nerve to and from the hair cell via the spiral ganglion cell are lost (both neuron and eventually the cell after a few months/years).

There is currently no way of reconnecting these or regenerating the SG cell.

I also think funding in this area is extremely low (looking at DoD and UK govs commitment's). Given the funding available I think researchers have done great but more money is needed.

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The article seems to suggest that the SG cell is also getting regenerated. See

> The new cells contained transduction channels that relay sound signals and the ability to form connections with auditory neurons — processes essential to hearing.

Are both cell types functional?

Incredible I think I missed that part. Afaik the only other drug shown to regenerate synapse in animals was a Bisphosphonates (Zoledronate acid).

There's further questions on the models. Using Guinea pigs and mice yeild different outcomes. There's also questions on whether adult mice are better suited for hearing research.

You seem to know your stuff.

My family suffers from a mitochondrial disease in which effects these very hairs in our cochlea (which makes us great candidates for cochlear implants) but would this be "simple" for research such as regenerating hair cells?

One of the reasons we make such good cochlear implant candidates is we instantly hear. It's like the neurons/links were just waiting.

If this is of interest to you, or you could perhaps point me in the direction of someone in this space, you can find my via my profile :)

I also thought of fx322 and oto313 (from another lab). Hearing regeneration and tinnitus healing are those things that seem "achievable " but are way more complicated than it seems initially.

The subreddit r/tinnitusresearch has good coverage of the scientific efforts. Which as you mentioned are not that many.

There's another promising candidate by Sound Pharmaceuticals. A synthetic compound, Ebselen

https://clinicaltrials.gov/ct2/show/NCT04677972

The trials have shown some degree of efficacy above controls. At this stage I only consider evidence from trials to get excited over, though it's important to be optimistic over lab results and research.

When I first starting doing more research I was surprised by the low funding and the fairly big number of affected patients. Why is there not more funding? Research is making steady progress so the field doesn't appear to be a money sink with nothing to show for.

Can you point me to some sources that back up your claim that neurons are damaged first and only later hair cells are lost as well. I always thought it’s the other way round.

Of course. There's an good video explaining this and also citing / explaining the same research. I made a error in my original post, it is the synapse* not neuron between the SG and audiotry nerve, and the IHC / OHC.

Hidden Hearing Loss: The Effects of Synaptopathy, Stanford.

https://youtu.be/ZGmPG94Rmr8

Thanks for following up.

I think there are different forms of hearing loss (hidden hearing loss, noice induced hearing loss, middle ear hearing loss, ...). I think noice induced hearing loss is most common nowadays and is caused by structural damage to hair cells. Regenerating hair cells might cure this particular form of hearing loss but not others. I think the one you mentioned has a different root cause for which new hair cells are only part of the puzzle.

The web was weird and wonderful. The cure was Facebook and Twitter.

Keep your cure for JS as far away from me as possible, thanks.

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