MAPT and Alzheimer disease: In a transgenic rat model (TgF344-AD) in which rats express mutant amyloid precursor protein and presenilin-1, rats show early hyperphosphorylation of tau in the LC, loss of hippocampal and cortical NE fibers, impaired reversal learning in the Morris Water Maze, and behavioral deficits were reversed with chemogenetic activation of the LC (Rorabaugh et al., 2017).