PTH and Alzheimer disease: To investigate the effect of PTH1-34 treatments on AD-relevant brain pathology, 5XFAD mice (both male and female) were administered with hPTH1–34 or vehicle (Veh) as illustrated in Fig. 3A. We first measured both human Aβ40 and Aβ42 levels in soluble fraction from brain homogenates (cortex and hippocampus) of 5XFAD female mice in response to PTH1-34 treatments.