Tinnitus: Map Theory

Inner ear cells Credit: Hertzano et al

Tinnitus really is a paradise for researchers. Many tinnitus sufferers are waiting for a cure. For example, a researcher could map each cochlear cell to its brain receptor, dendrite, or axon. 

Each one of the hairlike cells of the cochlea depicted in the photograph above generates an electrical signal when stimulated by noise. Each noise signal is transmitted to the brain by a nerve that resembles coaxial cable. When the signal arrives at its destination, in the brain, the noise is converted to sound. 

Imagine that some of the hairlike cells above are amputated at the base. What would happen? The answer is that the electrical noise signal that would typically be sent from the cochlea through the vestibular nerve and the auditory nerve, to the brain for interpretation, would not be generated. It is as if a postal employee decided to go on strike and left the mail sitting in a bin. Eventually, an intended recipient would start complaining about his or her missing mail. Tinnitus is like the intended recipient. It is complaining that it has not received a signal. 

When the signal is not sent to the brain, the brain interprets the absence by generating its own alarm (ringing, whooshing, buzzing, clicking, etc.) by oscillating. I realize that people with severe tinnitus believe that the ringing or buzzing sound is in the ears. It certainly feels that way. But it really is inside of the brain. The amputated cells of the cochlea are non-regenerative which is why the ringing does not stop once it is identified as chronic. Currently, there is no way to bring the cells back from the dead. Birds are able to regenerate these cells but humans are not able to do it.

In the future:

I theorize that the type of sound that the brain generates may help researchers to determine exactly where in the auditory center of the brain the connection is being lost and pinpoint the exact location of the specific receptor and interpretation neurons are located. 

If I am right, a pinpoint map should be able to be drawn, similar to how an electrician determines electrical panel malfunctions. It may look something like this...

If a ringing sound is heard then the damage is likely column X, row Y of the cochlear cells which connects to the auditory center of the brain at location Z. Z must therefore be inhibited.

If a buzzing sound is heard then the damage is likely column A, row B of the cochlear cells which connects to the auditory center of the brain at location C. C must therefore be inhibited.

If a clicking sound is heard then the damage is likely column D, row E of the cochlear cells which connects to the auditory center of the brain at location F. F must therefore be inhibited.

If such a map could be drawn then it may be possible, in the future, to inhibit the exact spots pinpointed for each patient. Such a map would lead a researcher down a few areas to explore. Using the map a researcher could try to trick the brain into responding to an artificial electrical signal that matches the signal of the specific cochlear cells that are damaged. 

Another option would be to completely shut down the associated dendrites and axons responsible for generating the alarm. As far as I know there are currently no microscopic instruments to create such a map. In the future, it may be possible to do so. I hope someone reads my map theory and is inspired to explore. 

The alarm (ringing, buzzing, whooshing, etc.) is telling us that something is wrong. The alarm occurs in the auditory center of the brain (and can be as far down as the brain stem), not in the ear. The alarm needs to be turned off at a precise location in the brain specific to each tinnitus sufferer's unique damage. I believe that there is a code to turning off this alarm for each person and researchers just haven't identified the code...yet. 

Some researchers have identified a general area of the brain for further study but it is not mapped to the specific damage for each person. Researchers are looking into using drugs to inhibit the general area of the brain that has been identified. Scalp electrodes have also been used. I don't think that either will work long-term because the precise location has not yet been mapped. If researchers use a drug to inhibit a general area in the auditory center then hearing loss may be a possible result because the researcher is treating healthy auditory system connections while attempting to treat unhealthy auditory system connections. If one cochlear cell is amputated then that cell should be treated, not the healthy unbroken cells. This should be done one at a time until the tinnitus sufferer is tuned up, theoretically. 

(The photograph above is from inside of a mouse cochlea. The principles are the same. The photographer has no affiliation with me, this blog, or my theory.)