What happens to the brain as we age and what can we do to prevent the effects of ageing, asks Courtenay Norbury
Trinity College Institute of Neuroscience is set to make a big impact in "translational neuroscience" with huge benefits for clinical practice, according to Prof Marina Lynch, director of the Institute.
Prof Lynch is concerned with the changes in the brain that occur when people get older. She has developed experimental models to demonstrate what mechanisms contribute to these changes and how they impact on an individual's ability to learn and remember new information and experiences.
Her research has demonstrated evidence of "stress" in the ageing brain. "In our models, we see an increase in oxidative and inflammatory stress with age," Lynch reports. This stress is directly linked with decreases in the brain's general performance.
In the central nervous system, tissues known as microglial cells act to scavenge cell debris. Under normal conditions, they are quiet, but they can become activated by any kind of stress.
When activated, they release substances that produce inflammation of surrounding tissues. Prof Lynch's research shows increased inflammation can disrupt "long term potentiation" (LTP), a process that enhances the ability of brain cells to do their job properly. LTP is thought by many to be the cellular basis of learning and memory.
In the experimental models, essential fatty acids and statins, drugs that are commonly prescribed to reduce cholesterol, have rapidly reduced the number of inflammatory substances, restoring normal function.
However, a certain level of microglial cell activation is necessary to perform its normal scavenging role. "We have a delicate balancing act here," Lynch warns.
The research has important clinical implications, as there is sufficient evidence that one of the changes that occurs in Alzheimer's disease is inflammatory change. Prof Lynch's model suggests that it should be possible to improve function by using readily available anti-inflammatory drugs and essential fatty acids.
Lynch says her centre is multidisciplinary oriented. "We are unique in being a truly multidisciplinary institute. Although in world terms we are a relatively small institute, our size enables close collaboration between scientists with different expertise," Prof Lynch says. "Because of this, we are able to test our hypotheses across the span from genes to molecules to cells to human volunteers to patient populations."
The arrival of a Magnetic Resonance Imaging (MRI) scanner last autumn is taking the research a step further. "Imaging is a new direction to the work we've been doing here," Prof Lynch reports.
TCIN houses the only research MRI facilities in Ireland. Prof Lynch sees the institute as a national resource and actively encourages scientists from other parts of the country to conduct neuroimaging work at TCIN. MRI will make it possible to look at the structures of the brain before and after treatment with fatty acids or anti-inflammatory drugs.
"The before picture will help us to see any neural markers for early brain changes. Being able to image the brain post-treatment will indicate markers of brain restoration." Such analyses should assist clinicians in identifying those patients for whom treatment may be most useful.
To facilitate work with clinical populations, the Health Research Board has recently agreed to fund a second imaging site at St Joseph's Hospital, for joint use by hospital clinicians and researchers from the TCIN. "These facilities will enable us to make a very significant impact [ in the fight against Alzheimer's disease] because of the translational approach into clinical practice," Prof Lynch says.
• Dr Courtenay Norbury is an experimental psychologist at Oxford University and a participant in the British Association for the Advancement of Science Media Fellow Programme