ABSTRACT
Amyloid is an extracellular mass of amyloid fibrils. The fibrils are 7-10 nm in diameter under electron microscopy (EM). In the brain, amyloids consist of amyloid β protein (Aβ), and they are associated with proteins such as α1-antichymotrypsin, apolipoprotein E, apolipoprotein J, vitronectin and non-Aβ component (NAC). Of these proteins, only NAC can be biochemically extracted from the deposited amyloid (Ueda et al., 1993). In the immunohistochemical study, labeling of senile plaques is different among antisera against these associated proteins. For example, anti-apolipoprotein E labels most plaques (Figure 1a) (Yamaguchi et al., 1994). Anti-apolipoprotein J labels neurons, amyloid angiopathy and a subset of senile plaques (Figure 1b).
