
Light Beam Lets the Deaf (Gerbil) Hear - 0xbxd
https://www.scientificamerican.com/article/light-beam-lets-the-deaf-gerbil-hear/
======
whymauri
This is very cool and technically challenging. I cannot imagine how hard it
was to get viral transfection in the ear like that! Seriously, props.

In almost all applications, optical stimulation theoretically (and in rodent
trials) outperforms electrical stimulation. Once we solve the immunological
roadblocks of optogenetics, I can imagine a huge spike in peripheral nervous
system applications. Perhaps not as much in the CNS, since deep brain
stimulation is a huge problem.

That being said, the immunological problem in optogenetics is the elephant in
the room. I think everyone in the field knows that long-term loss-of-
expression is heavily influenced by immune responses, yet are afraid to admit
it. Essentially, if transfecting adults with light-gated ion channels leads to
horrific immunological feedback, we could see people getting _worse_ as their
nerves are destroyed. I have seen this in my histological samples (PNS;
hindlimb; rats and mice) and have quantified denervation atrophy by post-
mortem weighing of muscle.

This is not a solved problem, even though a few promising solutions like drug
treatments and chimeric protein engineering are being discussed. I suspect
certain immunosuppressant drugs might be particularly effective. Despite the
risks above, start-ups are trying to take this very promising technology to
human trials. I personally find this reckless.

But I'm done with the negativity: the study in the OP is really awesome and
I'm rooting for them. I dream of a day when opto is advanced enough that
targeted, multi-color activation of sensory neurons is translated to people.
Imagine feeling force and touch with a prosthetic because it talks directly to
your nervous system... maybe one day :)

------
Jack000
hoping for some advances in this field personally, although not sure how to
feel given the other crispr related headline today. I became totally deaf in
one ear two weeks ago, presumably from a viral infection.

PSA: if you have sudden hearing loss, go to the ER immediately. I'm told the
ideal window for treatment is only 48 hours.

------
mwachs
Seems akin to [https://earlens.com/](https://earlens.com/)

~~~
UnderProtest
Not even a little bit but that's a fascinating device.

The hearing aid you linked uses light to activate a transducer that's been
placed against the tympanic membrane (eardrum). It could have used a wire,
radio waves, whatever.

This technique is a combination of a viral infection that transfers light-
sensitivity genes into the inner ear and a surgical implant that produces
light in the inner ear modulated in response to sound.

One is an externally worn device and the other is a combination of surgery and
viral gene-editing. They're "akin" in that they both use light as part of the
system. Well, I guess they also both use devices made from baryonic matter.

