Fig. 5. Manipulation of MAP kinase activity does not alter the transport or distribution of tau within axonal neuritis. (A) Representative fluorescent images of NB2a/d1 cells transfected 24 hours previously with a construct expressing CFP-htau40 with (+) and without (-) treatment with the MAP kinase inhibitor PD98059 for 2 hours. (B) Graph of the relative density of CFP-htau40 fluorescence, along with PHF-1, Tau-1 and 5E2 immunoreactivity within axonal neurites determined from 50-100 cells in duplicate cultures with or without PD98059 treatment for 2 hours. Note that PD98059 did not alter the distribution of newly transported (CFP-tagged) tau within axonal neurites, nor that of phospho-dependent (PHF-1, Tau-1) or independent (5E2) tau epitopes.