Effects of optogenetic locus coeurleus stimulation on functional connectivity in a rat model of Alzheimer’s disease

Activity of the locus coeruleus (LC) influences behaviors that go awry in prodromal Alzheimer’s disease (AD), and these abnormalities coincide with early accumulation of hyperphosphorylated tau in the LC. LC stimulation changes global functional connectivity, but it is unknown how AD‐like neuropathology affects the LC’s ability to regulate brain state. Therefore, we combined optogenetics and functional magnetic resonance imaging (fMRI) in the TgF344‐AD rats that develop endogenous hyperphosphorylated tau in the LC prior to amyloid or tau pathology in forebrain regions.