 The Mn2+ ion gives a hyperintense signal in T1-weighted MRI and thus serves as a contrast agent.Mn2+ enters through voltage dependent calcium channels, is taken into intracellular organelles and is transported by the endogenous neuronal transport system including kinesin-1, accumulating at distant locations.Statistical parametric mapping of Mn accumulation in time-lapse images provides detailed information not only about neuronal circuitry but also about the dynamics of transport within them, and the location of distal connections.