A MODIFIED NOR-SILVER IMPREGNATION TECHNIQUE FOR AMYLOID PLAQUES AND NEUROFIBRILLARY TANGLES - COMPARATIVE-ASSESSMENT

A modified nucleolar organizer region (NOR)-silver impregnation techni que was recently introduced allowing the simultaneous staining of neur ofibrillary tangles (NFT) and amyloid plaques (AP) in a single section . This impregnation technique proved to be very effective, rapid, of l ow cost, and to yield consistent results even in brain tissue fixed fo r long periods of time. In the present study, several silver impregnat ion and immunohistochemical techniques were applied and their reliabil ity for the demonstration of NFT and AP was analysed. The modified NOR stain allowed the reliable and simultaneous demonstration of both amy loid plaques and neurofibrillary tangles; this method produced better results than the standard silver impregnation techniques. It is only i n their early stages of formation that NFT cannot be detected by this method and, instead, immunohistochemistry for tau-2 is required. There was no significant difference in the staining properties for amyloid plaques between silver impregnation technique immunostain. the modifie d NOR and the anti-beta-A4 immunostain.