Object: Metabolite changes in an experimental lesion in the rat cortex and in the contralateral hemisphere after the intravenous administration of mesenchymal stem cells (MSCs) were assessed by proton MR spectroscopy to verify the impact of the cell treatment on the brain tissue.
Materials and methods: Wistar rats with a photochemical cortical lesion and transplanted MSCs or sham transplanted rats were examined. Proton spectra were obtained from the lesion and from the contralateral cortex.
Results: Magnetic resonance spectroscopy revealed a gradual recovery of the damaged tissue; however, we found no significant differences in metabolite concentrations in the lesioned hemisphere between treated and untreated animals. Higher concentrations of glutamate and N-acetyl aspartate were found in the contralateral hemisphere in cell-treated animals compared to untreated ones. Lesioned animals showed neurogenesis in the contralateral hemisphere; the number of newly generated cells in stem cell-treated animals was 50% higher than those observed in untreated animals.
Conclusion: No direct impact of cell transplantation was observed in the lesion. However, changes in the contralateral hemisphere suggest that the transplanted MSCs might stimulate repair processes and plasticity resulting in the generation of newborn cells, which might enable the faster adoption of the damaged tissue's function by healthy tissue.