The researchers at the University of Glasgow aim to implant a tiny microscope into the rodent that could monitor cellular changes and gather other data.
It is hoped that by studying spinal cells in the rat's vertebrae, scientists could monitor disease progression and how therapeutic effects work in living organisms, potentially reducing the number of animals sacrificed for research.
The £400,000 project is being funded by the National Centre for the Reduction, Refinement and Replacement of Animals in Research (NC3Rs) and the Engineering and Physical Sciences Research Council.
Lead investigator Professor Andy Harvey, of the School of Physics and Astronomy at the University of Glasgow, said: "The use of in vivo microscopic imaging is widespread for fundamental research using animal models in biomedicine, for drug discovery and tracking disease progression.
"Deep-tissue imaging is, however, highly invasive and so termination of the animal normally occurs after each measurement.
"For experiments involving testing with multiple time points, for example in studying disease progression or cell migration, termination of an animal for each time point can require the use of a large number of animals to achieve a reliable research outcome."
Prof Harvey said: "The microscope will be sufficiently small and configured to be minimally intrusive for animal comfort. The microscope will be like a pacemaker is fitted in humans with minimal or no discomfort."