Marja-Leena Linne aims to create a digital brain twin

What are your main research interests? 

I study how the brain and nervous system function. I am particularly interested in how cells and molecules and the processes they engage in bring about neural network activity and, ultimately, the ways in which the brain processes information and how our cognition emerges.

I consider myself a neuroscientist who conducts neuroscience in a highly interdisciplinary way, drawing on a wide range of approaches. Currently, my main focus is on developing computational models and simulations for brain research. 

Most of my research to date has been basic research. For example, my research group investigates which disruptions at the genetic and cellular signalling levels may contribute to the development of schizophrenia, and how memory function might be restored in Alzheimer’s disease. In this professorship, I aim to bring biomedical technology and biology into closer alignment with clinical needs and develop brain models that could, in the future, also support physicians in their work.

My long-term goal is to develop digital brain twins, meaning continuously updated simulations tailored to an individual patient’s condition that could be used to predict, for example, the progression of diseases. Physicians could also utilise computational biomarkers related to brain health, much in the same way that specific biomarkers are currently measured from blood samples to support diagnosis.

What makes your research significant?

We already understand the functioning of many other human organs in considerable detail. However, we know very little about the brain because we have only very limited access to it. We do not know exactly what goes wrong when a disorder develops nor how sensitive the system is.

Brain research has been conducted using human stem cells, but these involve 2D and 3D experimental model systems where cellular behaviour has been altered through cell culturing. In rodents, on the other hand, the underlying mechanisms may differ from those in humans. Quite simply, we cannot access the cellular level in a way that would enable us to gauge what is happening throughout the entire brain at the same time.

Together with my research group, I seek to bring together existing cellular and neurobiological knowledge and integrate it using the laws of physics and chemistry. It is not enough to piece together this information in our minds or on paper and then formulate hypotheses on that basis. We need concrete mathematical models. We were the world’s first research group to incorporate models of cellular-level phenomena into a whole-brain simulator and to alter the function of a single astrocyte within that environment. This makes it possible to understand how even a very small change can dynamically affect the entire system over time.

Photo: Jonne Renvall/Tampere University

How would you develop your field?

I would like to see neuroscience, computational sciences, biotechnology and medical technology integrated much more closely. I also hope that they will become parts of a single process within neuroscience rather than remaining as fragmented as they are today. I think that modelling is the glue that brings these different disciplines together.

Moreover, I hope we will develop digital platforms for education and research that integrate knowledge from these different fields, and that there will be biologists, engineers and medical professionals who can move between different areas of neuroscience in the future. Maybe this could also foster innovation.

I think about this also from the perspective of society and ordinary citizens. They too could gain a better understanding of brain health and of how different factors influence one another. After all, most people today have a reasonably good understanding of what happens in the heart and what is important for keeping it healthy.

What would you like to research next and why? 

We can run test simulations on our computers or on computing clusters. However, once we combine detailed cellular models with large volumes of data collected from the human brain, supercomputers become necessary. The next question, then, is how we can scale our brain simulator and modelling framework to an exascale computer capable of performing one billion billion calculations per second. We have only just begun this scaling work with funding from the Academy of Finland and the European Union.

Because highly detailed models already exist for the different types of neurons, one of my major ambitions is to create an astrocyte model that is morphologically i.e. structurally, biophysically and biochemically accurate. Astrocytes are the brain’s support cells, or glial cells, and they were in fact my original research focus before I moved on to studying neurons.

What do you do in your free time?

Science, research and teaching younger generations are, in a way, a lifestyle. As you get older, however, you become more conscious of the need to also have some free time. I enjoy exercise and spending time outdoors, but not to the point of pushing myself excessively. Cross-country skiing is one of my favourite activities, provided we have a good winter. I also enjoy wild swimming, though again, that depends on having a good summer. Going to the gym is part of my basic routine and helps me stay fit.

Because my work is quite demanding and sometimes requires a great deal of extra effort, it is important to do things that provide a complete counterbalance. From a brain researcher’s perspective, appropriately balanced physical exercise is essential for the nervous system and brain.

Recently, I have started to go to concerts, and I have found that very enjoyable. Most of my free time, however, is spent with my family and close friends. There is not much time left for anything else, especially since one has to sleep as well. And, in the end, sleep is perhaps the most important thing of all. Without sleep, neither the nervous system nor the brain can function properly.