MAPT and Alzheimer disease: Further in vivo support for the association between LC degeneration and tau pathology in AD came from two fMRI studies, in which the authors found that LC loss of activation was directly related to tau accumulation in the entorhinal cortex and cognitive decline [80], while amyloid accumulation had a more pronounced impact as a group differentiator (i.e., distinguishing between amyloid-positive and negative groups) rather than directly correlating with LC dysfunction [81].