APP and myalgic encephalomeyelitis/chronic fatigue syndrome: CFS in adult rats reduced hippocampal neurogenesis and impaired spatial (hippocampal-dependent) memory performance (Sportiche et al., 2010), and CFS in the APP/PS1 mouse transgenic model of AD pathology increased amyloid plaque burden in the hippocampus and cortex (Minakawa et al., 2017) and increased both amyloid-β42 (Aβ42) and markers of neuroinflammation in the hippocampus but not in the cortex (Duncan et al., 2022).