Ageing networks

As you get older, you may notice that it is not always as easy as before to recall words, and memorising a new person's name can cause difficulties. These changes in cognitive capabilities are not only problems connected with neurodegenerative disorders, such as Alzheimer's disease, but also part of normal ageing.

At the moment, researchers know fairly well which brain regions are activated in young people when dealing with linguistic problems, but they do not have such broad knowledge of older people’s brain networks. ‘We know that brain networks change with ageing. However, we do not know how they are connected with the deterioration of functional capacity, such as with the ability to remember words and names’, says Staff Scientist Mia Liljeström from Aalto University Department of Neuroscience and Biomedical Engineering.

Liljeström aims to bridge the knowledge gap between the brain networks of young and old people by studying how linguistic brain networks change with normal ageing. She carries out her research with the help of brain imaging and new computational methods.

Synapse loss in a part of the brain called the prefrontal cortex is considered to be one of the structural changes related to ageing in the brain’s network. Changes in the functional networks of the brain are assumed to reflect these structural changes. Due to such changes it is possible that a brain region of an elderly person is not activated in the same way as that of a young person. 

Seen from outside, changes in functional networks may appear as deteriorated cognitive functions.

To demonstrate the changes caused by ageing, Liljeström has to compare the functioning of brain networks in young and elderly test subjects. She has started collecting brain imaging data by performing MEG and MRI measurements of brain networks. A total of 25 young adults and 25 elderly adults take part in the study that began in summer 2019, and the research utilises the top-level technology of the Aalto Neuroimaging Infrastructure at Aalto University.

An understanding of normal ageing is essential when studying patients with Alzheimer’s disease

Understanding the changes related to normal ageing is a compulsory intermediate step for Liljeström on her way to reaching the long-term goal of her research. It is envisaged that the study will eventually lead to brain imaging of patients with Alzheimer’s disease.

Prior to this, it is necessary to know what happens in the brain with normal ageing, so that normal changes can be distinguished from those caused by the disease. According to Liljeström, changes in brain networks related to ageing and memory disorders can potentially be observed with MEG imaging before they can be detected through behavior.

Direct clinical benefits of an early detection of changes caused by Alzheimer's disease are expected to arise in the future, but there is no disease-modifying medical treatment for Alzheimer's disease as yet. ‘However, much effort is put into developing new medicines,’ says Liljeström. In the future, medical treatment will be most beneficial if the disease can be diagnosed at an early stage before irreversible structural deterioration has occurred in the brain.

The Päivikki and Sakari Sohlberg Foundation has granted funding of EUR 30,000 and EUR 20,000 for research in the grant application rounds of 2018 and 2019.

Further information:

DSc (Tech.) Mia Liljeström
Aalto University
mia.liljestrom@aalto.fi
+358 40 512 0212