ALTERATIONS IN GLUTAMATE-RECEPTOR 2 3 SUBUNITS AND AMYLOID PRECURSOR PROTEIN EXPRESSION DURING THE COURSE OF ALZHEIMERS-DISEASE AND LEWY BODY VARIANT/

Alterations in the processing and patterns of trophic and/or toxic fac tors might lead to the increased neuronal vulnerability in the entorhi nal cortex in Alzheimer's disease (AD) and Lewy body variant (LBV). Th erefore, patterns and levels of amyloid precursor protein (APP) and gl utamate receptor (gluR) expression in the entorhinal cortex and hippoc ampus in relation to disease severity were investigated. Sections from the hippocampus and entorhinal cortex were single and double immunola beled for APP, gluR2/3, and N-methyl-D-aspartate receptor (NMDA-R). Wi thin the hippocampus and entorhinal cortex, image analysis revealed pr ogressively decreased APP and gluR2/3 levels during the course of AD a nd LBV, whereas levels of NMDA-R were unaltered. Furthermore, the pres ent study showed a positive correlation and close co-localization of A PP and gluR2/3 immunoreactivity in neurons, suggesting a possible inte raction between these two factors. In conclusion, these data imply tha t alterations in neuronal APP and gluR2/3 expression in the entorhinal cortex lead to increased susceptibility to neurodegeneration and migh t be markers of vulnerability.