Studied neuron-like cell models (N2a neuroblastoma), cultured primary cortical neurons from rats or mice, and chicken retinal ganglion cells (RGCs) for the effects of tau overexpression. An N2a neuroblastoma cell line stably transfected with APP695 was provided by Drs. G. Thinakaran and S. Sisodia (University of Chicago, Chicago, IL).
Antibodies used in this study were rat monoclonal anti-tubulin YL1 (serotec), mouse monoclonal antibody DM1A (Sigma-Aldrich), polyclonal rabbit anti-tau antibody K9JA (Dako), and polyclonal rabbit anti-PMP69 antibody for peroxisomes (gift from Dr. W. Just, University of Heidelberg, Heidelberg, Germany). The monoclonal mouse antibody SMI32 (Sternberger) was used for the detection of unphosphorylated neurofilaments. The monoclonal tag antibodies from mouse against HA tag (12CA5) and myc tag were obtained from Roche Diagnostics and Invitrogen. Polyclonal anti-APP B5 (5313), (residues 444–592) was a gift from Dr. C. Haass (University of München, München, Germany), and monoclonal antibody 6E10 was from Senetek (now produced by Signet).