Linus Milinski is a PhD student in Professor Victoria Bajo Lorenzana’s laboratory at the University of Oxford. His project began in October 2018.
Tinnitus, or ‘ringing in the ears’, is a very common phenomenon – many people will have experienced temporary tinnitus after being at a music concert or when they have a cold. However, for more than 250 million people worldwide, their tinnitus is permanent, and greatly affects their quality of life. There is currently no cure for tinnitus – treatments for tinnitus focus on helping people to cope with it.
In most cases, tinnitus is created by the brain; it is also linked to age-related hearing loss or damage to the ear (for example, following loud noise exposure). It is thought that, after the ear becomes damaged, certain areas of the brain which usually process sound information, become persistently active, and that this leads to the sensation of tinnitus. But we do not know precisely what happens in the brain as tinnitus develops and progresses.
We also know very little about the link between tinnitus and sleep. Our brain activity is very different when we are awake and when we are asleep. In people with tinnitus, we don’t know how brain activity caused by tinnitus is affected depending on whether they are awake or asleep. Although tinnitus is only ‘heard’ when a person is awake, sleep disruption is common in people with tinnitus.
The main aim of this project is to understand the link between brain activity and tinnitus during waking and sleep, and how brain activity changes as tinnitus develops. The project will also look at whether sleep is affected by tinnitus, and whether poor sleep makes tinnitus worse.
Linus will measure brain activity in an animal model, both day and night, for several months before, during and after the development of tinnitus. Tinnitus will be induced by exposure to loud noise. Tinnitus and its severity will be measured using established techniques that are commonly used with animals. Linus will take long-term recordings of brain activity investigate whether being awake or asleep in the hours before and after tinnitus is induced affects the development of abnormal changes linked to tinnitus in the brain. He will also look at whether this is linked to how severe the tinnitus is, and whether sleep might play a protective role.
The results of this project will provide a better understanding of the processes in the brain that may cause tinnitus, and how tinnitus develops over time. These findings will help researchers to identify a time window where delivering a treatment for tinnitus will be most effective before it develops into a permanent condition. The findings may also provide information about how tinnitus affects sleep quality. This could lead to a new line of research looking at whether sleep could help to correct the abnormal brain activity that is linked to tinnitus.