Results of sabbatical

What was your goal in going on sabbatical to Edinburgh?

“My goal during the sabbatical was to establish contacts and to start a research project in an area new to me. This led to a collaboration with Edinburgh University in the field of medicine. The research concerns the connections between neurons, the synapses.

Why is this important? How can it contribute to our societal development?

“As we know, the aging of the brain is a major challenge to society, and the importance of this issue is increasing as our life expectancy increases. Why are different regions of the brain affected by disease as we develop and age? Moreover, our learning and memory capacity is to a large degree located at the synapses. Why does the small child think in a different way than the adult? How can schools be adapted to the way the brain works in different ages?

Brain function is the interplay between many interacting areas where the activities of nerve cells lead to our ability to see, to think and to act. Information processing, learning, and memory are believed to take place in the junctions between nerve cells, the synapses. From previous knowledge we know that synapses can be activating or braking, that they can take on a variety of shapes, and that different signal substances can be sent. By using a microscope to examine billions of individual synapses, we have shown that synapses are structured in a large number of different ways in purely molecular terms. Different parts of the brain also have different compositions of synapse types.”

What have you examined more closely in the project?

“We have found that compositions of synapse types change throughout our lifespan. The diversity of types first increases from birth until young adulthood, to then decrease during aging. However, even though there is a decrease in the complexity of the composition of synapse types in the aged brain down to levels comparable to the young, it is not a question of returning to the same types. It is a life-long development. Using computer models developed at KTH we can show how the development of synapse types can lead to a change over time in the brain's approach to processing information. Increased diversity facilitates a richer and more nuanced information processing but, at the same time, the complexity and the continuous change open the door to new risks and vulnerabilities.”

Why could this be important in the long run?

“It means we can increase our knowledge about how the richness in composition of synapses in brain regions and ages is associated with an evolutionary adaptation where the demands on the child, the adolescent, the adult, and the elderly are all different. The development in molecular terms of synapse structure could also explain why certain diseases affect the brain differently at different ages, and why certain areas of the brain are affected more than others.”

An article recently published in the journal Science gives more information on how the brain's synapses change from birth to old age (Cizeron et al., Science methods, 2020).

Article in Science