In Vivo Evidence of Axonal Transport Perturbation in a Mouse Model of Tauopathy : A Track-Tracing Memri Study

Anne Bertrand^1,2, Minh D. Hoang², Dmitry Novikov², Susan Pun², Pavan Krishnamurthy¹, Hameetha Banu¹, Benjamin Winthrop Little², Einar M. Sigurdsson¹, Youssef Zaim Wadghiri²

We report a track-tracing MEMRI in a mouse model of tauopathy (P301L line). We compared transgenic and wild-type animals at an early stage (6 month-old), using a long timeframe protocol (9 consecutive MR examinations for each mice) and a mathematical modelization of axonal transport using a drift-diffusion model. We show that P301L mice display significant differences in 2 parameters of axonal transport : the value of the peak of Mn, and the time of the peak of Mn. We also observed trends in drift velocity V, leakage rate λ and apparent speed of Mn transport that were smaller in TG mice that in WT. This provides the first in vivo evidence of axonal transport impairment assessed by MRI in a model of tauopathy.