To determine if the presence of AD-associated Aβ pathology alters brain uptake of IRAs delivered IN, we also tested the uptake of the single and dual IRAs showing greatest brain uptake after IN administration (i.e., dulaglutide and DA4-JC, respectively) in a transgenic model of AD, namely APP/PS1 mice, specifically in adult male and female wild-type (WT) and hemizygous APP/PS1 littermate mice. Here, APP is linked to Alzheimer disease.