The human brain is made up of a complex network of neurons. These neurons serve as the building blocks of the nervous system, transmitting information to and from the brain and throughout the body. Though, the human brain contains around 100 billion neurons.
Now, a team of Swedish researchers at Karolinska Institutet has discovered three new types of neurons in the peripheral auditory system. These neurons carry auditory signals from the ear to the brain and may hold the secrets to treating hearing disorders like tinnitus.
At the point when sound reaches the internal ear, it is changed over into electrical signs that are handed-off to the brain by means of the ear’s nerve cells in the cochlea. Already, the greater part of these cells was thought to be of two kinds: type 1 and type 2 neurons, type 1 transmitting the majority of the sound-related data.
Another investigation by researchers at Karolinska Institutet demonstrates that the type 1 cells really include three very different cell types, which counts with prior research indicating varieties in the electrical properties and the sonic reaction of type 1 cells.
François Lallemend, research group leader at the Department of Neuroscience, Karolinska Institutet, who led the study said, “We now know that there are three different routes into the central auditory system, instead of just one. This makes us better placed to understand the part played by the different neurons in hearing. We’ve also mapped out which genes are active in the individual cell types.”
“Our study can open the way for the development of genetic tools that can be used for new treatments for different kinds of hearing disorders, such as tinnitus. Our mapping can also give rise to different ways of influencing the function of individual nerve cells in the body.”
Scientists conducted their study on mice. For this, they used a new technique of single-cell RNA sequencing. The outcome is a list of the genes expressed in the nerve cells, which can give researchers a strong foundation for better understanding the sound-related system and also to devise new treatments and medications.
The investigation demonstrates that these three neuron composes most likely have an impact in the translating of sonic intensity (i.e. volume), a capacity that is crucial amid discussions in a loud situation, which depend on the capacity to sift through the background noise. This property is likewise vital in various types of hearing the issue, for example, tinnitus or hyperacusis.
Dr Lallemend said, “Once we know which neurons cause hyperacusis we’ll be able to start investigating new therapies to protect or repair them. The next step is to show what effect these individual nerve cells have on the auditory system, which can lead to the development of better auditory aids such as cochlear implants.”
The study is published in the journal Nature Communications.