Functional MRI scans of rats are indispensable for research into brain disorders. Joanes Grandjean of Radboudumc developed a new standard protocol for these scans. This improves quality and makes it easier to compare results from different studies. This prevents repetition of studies and leads to less use of laboratory animals.
A functional MRI scan is a variant of the well-known MRI scan. Such a functional scan maps the brain’s oxygen consumption and thus measures the activity of various brain regions. This allows us to better understand the healthy brain and to investigate what goes wrong in neurological disorders. Think of Parkinson’s disease, Alzheimer’s or MS. Research into the causes of these diseases and the effects of new medicines is of great importance. But just testing new medicines on people is not and is not allowed. This also applies to the removal of brain tissue for further examination.
This is where laboratory animals come into the picture. Literally even. You can make both functional MRI scans and take brain tissue from laboratory animals. Research into brain disorders usually uses rats. However, researchers all perform these scans slightly differently. This makes comparison of scan results difficult. That is why many studies are being repeated, resulting in more laboratory animal use. There must be room for improvement, thought neuroscientist Joanes Grandjean, who works at the Donders Institute and Radboud university medical center.
Standard protocol for scans
Grandjean contacted colleagues from home and abroad. He asked them how they performed the scans and whether they wanted to share their results. There was a great response: In the end, more than 200 scientists from 46 centers participated. Together they provided scans of more than 800 rats. ‘That is unique for laboratory animal research,’ says Grandjean. ‘Researchers are often very careful about sharing their data. They are afraid that others will run off with it.’
With so much data, Grandjean and his colleagues were able to determine the best way to scan rat brains. For example, they investigated 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 that improves the reliability of the scan data by fifty percent. The protocol is freely accessible to researchers. Grandjean: ‘We call on scientists: Use our protocol and make your data available to others. In this way we strengthen neurological research across the board and we reduce the use of laboratory animals.’
This is endorsed by Judith Homberg, professor of translational neuroscience at Radboudumc and co-author of the article. ‘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 repeating studies and wasting laboratory animals.’
In laboratory animal research, the so-called 3 Rs are taken into account as much as possible: replacement, reduction and refinement. This research makes an important contribution to the last two spearheads. Homberg: ‘This is a big step. Especially for complex diseases, such as those of the brain, we cannot yet do without animal research. That’s why we have to use the laboratory animals we use as effectively as possible.’
About the publication
This research is published in Nature Neuroscience: StandardRat: A multi-center consensus protocol to enhance functional connectivity specificity 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 Radboudumc co-authors: CCG Guo, MJAG Henckens, X. Meng, A. Rivera-Olvera, R. Vertullo, RM Vrooman, CF Beckmann, JR Homberg, DJ Houwing, A. Heerschap, TJ Scheenen, A. Veltien.