Figure 3.

The diffusion barrier depends on intact microtubules. (A) Green fluorescent image of an 11 DIV neuron transfected with Tau^D2 for 2 days before photoconversion. (B) Red fluorescent image of the same neuron immediately after illumination of its axon near the soma (ROI1) with UV light. (C) Time-lapse images up to 30 min show the anterograde diffusion of axonal Tau but retrograde blockage at the initial axon (arrowhead) so that Tau^D2 does not enter the cell body (dashed circle). At 30 min, cells were treated with 5 μM nocodazol to disrupt microtubules. (D) After addition of nocodazol, there is diffusion of Tau^D2 across the barrier in the initial axon (arrowhead) into the somatodendritic compartment (dashed circle). Data represent at least three independent experiments.