Fourteen month old TNWT-61 mice and wild-type (WT) littermates underwent DKI scanning using 9.4 Tesla MRI system in vivo. TBSS and ROI analysis was performed to detect the changes in white and gray matter in TNWT-61 and WT mice. Immunohistochemistry for alpha-synuclein was performed in 5 TNWT-61 mice and correlated with DKI findings.
The principle findings of this study were increase in mean kurtosis and decrease in mean diffusivity in thalamus, sensorimotor cortex, hippocampus, external capsule and basolateral amygdaloid nucleus in 14 month TNWT-61 mice as compared to WT littermates. We also found significant correlations between alpha-synuclein accumulation and increase in kurtosis and decrease in diffusivity in the thalamus.
Our results reveal that DKI is sensitive in detecting microstructural changes due to alpha-synuclein accumulation in both GM and WM. These findings suggest that in PD patients DKI should be preferred to routine DTI despite a longer acquisition protocol.