Fig. 1.

Levels of total tau and tau phosphorylated at individual phosphorylation sites during development. (A) Equal amounts of brain homogenates from rats with the indicated ages were analyzed by Western blots developed with antibody 92e to detect total tau or several phosphorylation-dependent and site-specific tau antibodies to detect tau phosphorylation at the individual sites. (B–E) The blots shown in panel A were quantified densitometrically, and the mean values of each time point were plotted against ages. The data represent relative immunoreactivities, those of which at birth (P0) were defined as 1. For quantification of tau phosphorylation, the data had been normalized by the level of total tau, as determined by 92e blots, at each time point. According to the patterns of changes, alterations of site-specific tau phosphorylation were divided into three groups and are presented in (C), (D), and (E).