Image analysis microspectroscopy of senile plaque capillary amyloid in Alzheimer's disease

The relationship between cerebral amyloid and the microvasculature in senile plaques was studied with image analysis microspectroscopy. This imaging technique permitted topography quantification of amyloid concentration within microscopic subregions of single senile plaques. The highest concentration of amyloid was measured at the walls of intraplaque capillaries. Spectroscopic images revealed a decreasing gradient of amyloid concentration with increasing distance from intraplaque capillaries. The concentration of amyloid in nonplaque capillaries was lower than that measured in capillaries within well-developed amyloid plaques. These findings support the premise that plaque amyloid deposition starts at the level of the capillary.