Research Article

Accumulation of Vesicle-Associated Human Tau in Distal Dendrites Drives Degeneration and Tau Secretion in an In Situ Cellular Tauopathy Model

Figure 1

ABC morphology. (a) shows a confocal micrograph of a wholemounted lamprey brain with an ABC expressing low levels of human tau and showing its characteristic gross morphology. Note that tau (red channel) is evenly codistributed with tubulin (DM1A-green channel), resulting in a yellow appearance. Tubulin immunolabel in axons from large reticulospinal neurons other than ABCs (RSpA) can be seen in whole mount (a) and in cross-section (c), and a Mauthner’s cell lateral dendrite can be seen in the whole-mounted preparation (MthD). (b) Dorsal view of a live lamprey brain with a pair of ABCs expressing exogenous GFP-tagged protein. Ten-micron-thick transverse paraffin sections were taken through the soma and dendritic fields of tau-expressing ABCs (upper line) and though ABC axons in the caudal hindbrain near the obex (b, bottom line). (c) Somatodendritic section through an ABC expressing low levels of Tau24 (4R0N tau). Both the whole- mount in (a) and the top section shown in (c) were immunostained with the mAb DM1A for total alpha-tubulin and anti-GFP for total exogenous tau. The bottom image is of a transverse section though ABC axons in the caudal hindbrain near the obex (at the level indicated in (b), bottom line). Scale bars: (a) 100 μm, (b) 200 μm (c) 50 μm.
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