Rewrite the textbooks! The cerebellum is more than just motor function

Open any medical encyclopaedia and it will tell you that the cerebellum controls functions such as balance and fine motor skills. But medical professionals around the world will now have to broaden their conception of the cerebellum as a place that is ‘just’ connected with our ability to precisely coordinate large and small movements. 

This is one of the perspectives in a scientific article titled “An atlas of the protein-coding genes in the human, porcine and mouse brain”, which has just been published in the journal Science. In the article, researchers from universities in number of countries, including at Aarhus University, have mapped how different genes are expressed in different parts of the brain across species. One surprising result is the cerebellum’s over-representation of genes that are linked to psychological disorders.

"There's no doubt that we’re going to take the cerebellum much more seriously in relation to psychological disorders, for example when developing new medicinal products in terms of where precisely they should have an effect,” says Associate Professor Yonglun Luo from the Department of Biomedicine at Aarhus University. 

"This knowledge fundamentally changes our understanding of the brain, which in turn means that while textbooks and reference works won’t need to be rewritten, they will have to be revised and expanded," adds Yonglun Luo.

Comparisons across species

Yonglun Luo is particularly involved in the part of the study relating to the mapping of the brains of pigs, which are known for their many similarities with humans in terms of anatomy, physiology and digestion/metabolism. The new atlas also further emphasise that pigs are genetically closer to humans than mice, says one of the study’s other co-authors, Professor Lars Bolund, who also comes from the Department of Biomedicine at Aarhus University.

"One of the many qualities of the study is that the new atlas is comparative – that we can make comparisons across species. This is an important tool for understanding the evolution and diversity of life at all levels," says Lars Bolund. The focal point of his work is how different functions have evolved from an evolutionary and biological viewpoint. 

Lars Bolund conducts research into regenerative medicine. His work is particularly focusing on the ability of organisms to self-repair, such as the salamander which can restore limbs and organs and grow a new tail. His workplace is in China at the Lars Bolund Institute of Regenerative Medicine located in Qingdao.

"The different animal species have 'solved' their challenges in slightly different ways. Taking pigs, they have a sense of smell that is far better than humans, and this means that many more genes contribute to this ability. There is much for us to learn by comparing the genetic abilities of different species and finding factors that can contribute to better prevention and treatment when our own abilities fail us," says Lars Bolund.

The comparative atlas is available as an open access resource under the title The Human Brain – Introduction to the Human Protein Atlas and is freely available to all researchers around the world, including hospitals and other research institutions. As Yonglun Luo explains, there are good grounds for this:

"Animal models are valuable for the development of new forms of treatment, and “The Brain Atlas” illustrates the importance of choosing the right animal for the study of special neurological processes. It’s also important to know your animal model well when developing and testing new treatments for humans," he says.

More about the research results

• The study maps the landscape of gene expression in different regions of the human, pig and mouse brain.
• Researchers from the Swedish Karolinska Institute are leading the study, not least Evalina Sjöstedt and Jan Mulder. The partners from Aarhus University include Lin Lin.
• The external funding came from the Sanming Project of Medicine in Shenzhen, the Lundbeck Foundation and the DFF Sapere Aude Starting Grant.
• The scientific article has been published in the journal Science: https://science.sciencemag.org/content/367/6482/eaay5947

Contact

Associate Professor Yonglun Luo
Aarhus University, Department of Biomedicine
Email: alun@biomed.au.dk
Mobile: (+45) 2241 1944 

Professor Lars Bolund
Aarhus University, Department of Biomedicine and
BGI Genomics, Lars Bolund Institute of Regenerative Medicine
Email: bolund@biomed.au.dk
Mobile: (+45) 2899 2544