This is a PhD studentship being carried out by Silvia Prades in the laboratory of Dr Dan Jagger at the UCL Ear Institute. Her project started in October 2016 and will end in September 2019.
Silvia's work will give us a better understanding of the causes and processes underlying tinnitus and auditory neuropathy.
Information regarding sound is normally carried from the inner ear to the brain via the auditory nerve. Loud noise or certain drug treatments can cause the nerve to become 'over-excited' – this can lead to tinnitus.
In addition, certain forms of hearing loss are also caused by damage to the auditory nerve – this is known as auditory neuropathy. The auditory nerve consists of a group of nerve cells called spiral ganglion neurons. These neurons rely on a type of cell called a glial cell for their long-term survival, under both normal and diseased conditions. Glial cells have many important functions; in fact, without them, the auditory nerve would not work properly.
Glial cells ‘micro-manage’ the local environment of nerve cells, continually removing poisonous substances and supplying essential nutrients, both of which are crucial for optimum nerve functioning. To do this, glial cells have to communicate both between themselves and with nerve cells – failures in this communication are responsible for various other nerve conditions such as chronic pain and migraine. Such communication failures within the auditory nerve may also be responsible for some types of tinnitus and auditory neuropathy.
Silvia is studying the processes that normally control communication between cells in the healthy auditory nerve, and also under artificially imposed conditions that mimic trauma or genetic disease. Using various experimental approaches, she will identify the chemical signals released by spiral ganglion neurons, and detected by glial cells during high levels of activity.
By obtaining a better understanding of the interaction between glial cells and the auditory nerve, Silvia may help us come up with treatments to lessen or prevent the development of tinnitus following noise damage. And, if we have a better understanding of the structural and functional relationships between neurons and glial cells, we could improve the design of cochlear implants.