Simultaneous imaging of amyloid deposition and cerebrovascular function using dual-contrast photoacoustic microscopy

Pathological aggregation of Aβ peptides results in the deposition of amyloid in the brain parenchyma (senile plaques in Alzheimer's disease [AD]) and around cerebral microvessels (cerebral amyloid angiopathy [CAA]). Our current understanding of the amyloid-induced microvascular changes has been limited to the structure and hemodynamics-leaving the oxygen-metabolic aspect unattended. In this Letter, we report a dual-contrast photoacoustic microscopy (PAM) technique, which integrates the molecular contrast of dichroism PAM and the physiological contrast of multi-parametric PAM for simultaneous, intravital imaging of amyloid deposition and cerebrovascular function in a mouse model that develops AD and CAA. This technique opens up new opportunities to study the spatiotemporal interplay between amyloid deposition and vascular-metabolic dysfunction in AD and CAA.