Functional hyperconnectivity is associated with higher levels of sPDGFRβ, a marker of blood brain barrier breakdown, in older adults

Apolipoprotein E4 (APOE4) has toxic effects on the cerebrovascular system, neuronal function, and functional connectivity of brain networks (e.g., default‐mode, frontal‐attention, and salience networks). The thalamus, a vital structure that acts as a relay station between many networks, has become of interest in AD research with studies showing atrophy among those with early AD and diminished cortical‐thalamic connections among those with vascular impairment. Additionally, CSF soluble platelet‐derived growth factor receptor‐β (sPDGFRβ), a marker of blood‐brain barrier breakdown, has been associated with AD risk, especially in APOE4 carriers. The present study investigated the relationship between CSF sPDGFRβ and functional connectivity in APOE4 carriers and non‐carriers.