Researchers at UCL’s Ear Institute are using a unique machine to deepen their understanding of how the brain processes sound. This is important for deafness as the brain deciphers soundwaves and an improvement in understanding this process has the potential to improve how deafness is treated or managed.
The Ear Institute’s new small-animal magnetoencephalograph, or MEG for short, is the most advanced machine of its type in the world.
The team hopes the research it makes possible will lead to advances in treatments for deafness and a range of other conditions.
Magnetoencephalography is an imaging technique used to measure the fluctuations of magnetic fields in the brain that occur as a result of neural activity. It complements other brain activity measurement techniques such as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI).
MEG has many uses, including localising a pathology and determining the function of various parts of the brain.
MEG has been used on humans for some time, but until now the machines have not been sufficiently sensitive for use on small animals.
But the Ear Institute’s machine, developed by KIT, takes the technology a step further, allowing much more precise measurements than were previously possible.
It uses specially designed, super-cooled sensors to measure the tiny fluctuations of magnetic fields in the brain, which are several orders of magnitude lower than the Earth’s magnetic field.
Researchers Dr Maria Chait, Dr Jennifer Linden, Dr Alain de Cheveigne (CNRS) and Professor David McAlpine are currently fine-tuning the machine for a series of experiments in small rodents.
Dr Chait said: “Sound is a pressure wave in the air that is converted by the ear into nerve impulses sent to the brain. We want to understand how the brain processes that information to create our perception of the world. Understanding that is one of the keys to progress in applications such as hearing aids, cochlear implants and a whole host of neurological disorders.”
An important aspect of the team’s research will involve measuring neural activity in the brains of genetically modified mice, bred to mimic a range of human brain disorders.
Dr Chait said: “MEG has been used widely to study human brain activity. However, a difficulty exists in relating the results of such work in humans to what we know about the structure of the brain, where information largely comes from animal model studies. We’re hoping this machine, which is a completely new technological advance, will allow us to bridge the gap between human and animal research leading to a major progress in understanding hearing and its disorders.”
The technique is non-invasive and the animals are not harmed in any way.
“A lot of the experiments we plan to do relate to studying the effects of long-term exposure to sound environments on the development and function of the auditory system. These experiments are fundamental to the understanding of how the sound environments in which we live affect our long-term hearing, but for obvious reasons are impossible to conduct on humans. Because these experiments involve repeating measurements over a long period of time they are also quite difficult to conduct using an invasive technique in animals. But with the MEG, we can raise the animals from birth to adulthood in specifically controlled sound environments and observe how such exposure affects the development of their hearing,” said Dr Chait.
The team also believe that the small animal MEG could be useful to the wider scientific community at UCL.
Dr Linden added: “The Kanazawa Institute chose UCL because they wanted a high-profile partner that could make proper use of the machine. It’s a really exciting piece of technology, but the potential is not limited to research at the Ear Institute. This brain imaging technique could be of benefit to scientists studying other brain functions besides hearing.”