Imaging of brain TSPO expression in a mouse(model of amyotrophic lateral sclerosis with 18F-DPA-714 and micro-PET/CT.

The feasibility and sensitivity of the TSPO radiotracer 18F-DPA-714 for the study of microglial activation in the brain and spinal cord of transgenic SOD1G93A mice, a model of ALS, was evaluated using high-resolution PET/CT and immunohistochemistry.
The results showed that a significant increase in 18F-DPA-714 uptake can be measured with high-resolution PET/CT in the brainstem of symptomatic SOD1G93A mice as compared to WT SOD1 mice. Moreover, immunostaining revealed that TSPO expression was increased in the brainstem nuclei and was colocalized with Iba1 immunoreactivity, suggesting that increased microglial activation might underlie at least in part the increased brainstem 18F-DPA-714 uptake.
Overall the results of this study suggest that micro-PET and 18F-DPA-714 might be a useful tool for the study of microglial activation in the SOD1G93A mouse model and strengthen the high relevance of combined preclinical PET and immunohistochemistry for the cellular characterization of the PET signal in vivo.