Hidden Hearing Loss, Tinnitus and Trouble Hearing Conversations in Noise

Does anyone know what the protocol for the so called binaural hearing test that's supposed to detect hidden hearing loss?

Yeah, I saw that one. It is almost hurtful to see the expression on Matt's face.

No need to tag. When you quote someone they will get an alert. So you have to either tag or quote to get their attention.

 

@Jim51042 I am not convinced. You are quoting another member on this forum. Quote an article rather.

As for what cells they are using, it says in the Sheffield university article, "using cell lines developed by Sheffield researchers". So the cells they use are likely stem cells. But that doesn't mean that they just inject a bunch of stem cells. They have to label them too in order to show that the treatment works. Also, they would have to differentiate the cells.

There are stem cells and dormant progenitor cells in the ear already, but you don't see them differentiating naturally following a damage (something Frequency Therapeutics, among others, are trying to change with their therapy). If they are injecting cells, then they have already differentiated them in a dish. Meaning they are no longer stem cells when they inject them.

Where do you get the idea that "glial stem cell approach would only regenerate damage hair cells"? They would not regenerate damaged hair cells at all. They are glial cells.

http://www.medicinenet.com/script/main/art.asp?articlekey=11382

Nerves are regenerated naturally in the PNS. Have a look at how this works. The mechanism would be similar in cochlear nerve regeneration. The cochlear nerve belongs to the PNS, but it's a cranial nerve, so it doesn't regenerate naturally. The only cranial nerve that regenerates naturally is the olfactory nerve and its receptor cells. If you want to regenerate the cochlear nerve, you will want to mimic the mechanism found in olfactory nerve or one of the nerves branching off from the spinal cord.

 

I'm not sure where you picked up "glial stem cell approach" or why you are quoting Bill. I don't mean to be rude or anything, but you seem to have conceptual misunderstanding. I am not a professor myself, but let me tell you what I know. Glial scar has nothing to do with hair cells. Alright?

I will quote Bill here just for reference.

There is a lot of content here. It's a lot to take in, and I won't go over all of this. So let me jump back to glial scar right away.

Glial scar refers to scar formation in the nervous system. Not in sensory cells! Hair cells are the sensory receptor cells of the cochlea, the organ of hearing. They are not nerve cells. Therefore, glial scar has nothing to do with them, or at least not directly.

Most commonly, glial scar refers to scar formation in the central nervous system, not in peripheral nervous system. Scar formation in the CNS is thought to be a major obstacle to recovering from neurodegenerative diseases like Parkinson’s. It's a way for the brain to protect itself, so that the degeneration may not spread to other areas of the brain. That's why it forms these glial scars.

Glial scars are formed by glial cells. Glial cells are not neuronal cells. Instead, they provide support and protect neuronal cells in both CNS and PNS. Which explains why they form these scars - to protect the surrounding nerve cells!

Overcoming the glial scars is kind of a central idea in treating diseases like Parkinson's. The promise of treating Parkinson's, Alzheimer's and Huntington's is in large held back by glial scars. As far as I know, cell transplants are the only way to treat these diseases. But so far, scientists have been trying to get past these scar formations and physically guide the transplanted cells into the right place. So this is where the idea of placing the cells on top of the glial scars comes from, which has been shown to be more effective, if not completely necessary. We have been doing it wrong the whole time.

Now we come to glial scars of the auditory nerve. Now that you know the historical context, you understand why and how this would work. Scientists would place the stem cells on top of glial scars to help restore synapses with the hair cells.

Have a look at the image below and take note of how the cells are injected. To the right you see the traditional approach where the needle enters the glial scar before the cells are release into the scar. To the left you see the new approach where the cells are released next to or on top of the glial scar.


You will find the article here:
https://atlasofscience.org/transplanted-cells-reveal-potential-for-functional-neural-regeneration-2/

 

http://www.nature.com/nature/journa...re17318.html?lang=en&WT.ec_id=NATURE-20160414

The "long-held dogma"! This leads me to believe that some doctors, and even some researchers are just plain idiots. They are too afraid to try new ideas! They like to keep to the old teachings, like it's a God given truth. They keep to their comfort zone. What do they care, they have their paycheck at the end of the month whatever they do. Thank God for people that stick their neck out and put their career and reputation on the line every few decades or so. If it were not for them we would be completely lost.

I know that bit is about spinal cord injury. But any new knowledge is welcome, because it often means that it can be applied to other areas as well. Like this whole discovery of "surface transplantation" in attempts to repair nerve damage in the auditory system.

https://www.ncbi.nlm.nih.gov/pubmed/26080415

 

"Reactive glial cells are like police vehicles, ambulances, and fire trucks immediately rushing in to help -- but these rescue vehicles can cause problems if too many of them get stuck at the scene. The problem with reactive glial cells is that they often stay at the injury site, forming a glial scar and preventing neurons from growing back into the injured areas"

~ Professor Gong Chen, Penn State University, 2013
http://science.psu.edu/news-and-events/2013-news/Chen12-2013

Here is the actual paper:
http://www.cell.com/cell-stem-cell/fulltext/S1934-5909(13)00550-X

That's true! Not in humans, no. They have only been done on animal models. But we may not need to do cell transplants. There is a new approach of using microsurgery and gene therapy to convert the glial cells into neural cells for localized injuries. This is the work of Gong Chen and his team.

There is also a drug therapy under development that could be used in more spread out injuries, or in degenerative diseases like Alzheimer's. The goal is the same, converting glial cells into neural cells. This is also the work of Gong Chen and his team. They showed that up to 90% of the glial cells were successfully converted into neurons.

Yeah, I may have used the wrong word there. I mainly posted the link to reference the image source. I think the that image is very informative, and it's not to be found in the original "article article". But it is provided by the team from Kyoto University.

 

They are not approved in human subjects. In animals... well, I don't want to rise the ethical debate, but who would stop you? Besides, you will probably not find Alzheimer's in an animal.

The problem of cell transplants is that many of the cells will die in the process. Most of them will be rejected by the immune system. Their survival is limited. The surviving cells' ability to integrate with the host cells and form neural circuits is also limited. Also, brain tumors can develop. For these reasons, scientists have started to look for other options. One of these is based on reprogramming glial cells into neurons.

As you can see there are many different approaches to degenerative diseases, nerve regeneration, etc. It's too much to cover in this forum perhaps. The discovery that cell transplants work better if you transplant them on the surface of the glial scar, rather then into the scar, is an important clue. If we ever need to do cell transplants, that's how we would do it. But science has progressed further than that. We are now talking about reprogramming glial cells into neurons. This mostly relates to diseases of the CNS. But the article you linked to above relates to the PNS and it's on the same track as these new approaches for treating CNS diseases. They talk about switching, i.e. reprogramming glial cells of the PNS (Schwann cells) into "repair mode".