Functional MRI scans of rats are indispensable for research into brain disorders. Joanes Grandjean of the Radboudumc developed a new standard protocol for these scans which greatly improves their quality and comparability. This prevents repetition of studies and reduces laboratory animal use.
A functional MRI scan is a variant of the well-known MRI scan. Functional scans map the oxygen consumption of the brain and thereby measure the activity of different areas of the brain. This allows for better understanding of the healthy brain and to study what goes wrong in neurological disorders, such as of Parkinson's disease, Alzheimer's disease or MS. Research into the causes of these diseases and the effects of new drugs is very important. But simply testing new drugs on humans cannot and should not be done. This also applies to obtaining brain tissue for additional research.
This is where laboratory animals come into the picture. Literally. In laboratory animals, it is possible to can make functional MRI scans and obtain brain tissue. Research into brain disorders usually involves rats. However, researchers perform these scans in a slightly different manner, which makes the results difficult to compare. Therefore, many studies are repeated, which increases the use of laboratory animals. Neuroscientist Joanes Grandjean, who works at the Donders Institute and the Radboud university medical center, thought that there must be a better way of doing this.
Standard protocol for scans
Grandjean contacted colleagues in the Netherlands and abroad. He asked them how they performed the scans and whether they wanted to share their results. The response was overwhelming: In the end, more than 200 scientists from 46 centers participated. Collectively, they provided scans of more than 800 rats. 'That is unique for laboratory animal research’, Grandjean says. ‘Researchers are often reluctant to share their data.'
With so much data, Grandjean and his colleagues were able to determine the best way to scan the brains of rats. For example, they examined the effects of different types of anesthesia and scanner settings on the quality of the data. In the end, they developed an optimized standard protocol, which improves the reliability of the data by 50 percent. The protocol is freely available to researchers. Grandjean: ‘We call on scientists: Use our protocol and make your data available to others. This will strengthen neurological research across the board and reduces the use of laboratory animals.'
Judith Homberg, professor of translational neuroscience at Radboudumc and co-author of the article, agrees. 'This standard protocol prevents researchers from having to reinvent the wheel. It also allows us to compare the results of different studies much better. This prevents repetition of studies and waste of laboratory animals.'
Experimental animal research takes the so-called 3Rs into account as much as possible: replacement, reduction and refinement. This study contributes significantly to the last two aspects. Homberg: 'This is a big step. Especially for complex diseases, such as brain disorders, we cannot yet abandon experimental animal research. Therefore, we need to use the laboratory animals we do use as effectively as possible.'
About the publication
This study was published in Nature Neuroscience: A consensus protocol for functional connectivity analysis in the rat brain. J. Grandjean, G. Desrosiers-Gregoire, C. Anckaerts………G.A. Devenyi, M.M. Chakravarty, A. Hess. DOI: 10.1038/s41593-023-01286-8.
Other co-auhors of Radboud university medical center are: C.C.G. Guo, M.J.A.G. Henckens, X. Meng, A. Rivera-Olvera, R. Vertullo, R.M. Vrooman, C.F. Beckmann, J.R. Homberg, D.J. Houwing, A. Heerschap, T.J. Scheenen, A. Veltien.