Molecular alterations of protein tau in the cingulate cortex of human brain with Alzheimer’s disease

Abstract

AbstractBackgroundAlzheimer's disease (AD) brain tissue at different stages were examined to compare the events of protein tau hiperphosphorilation and its assemble into Neurofibrillary tangles (NFT) in the hippocampus and the cingulate cortex and how this may be involved in the appearance of the Behavioral and Psychological Symptoms of Dementia (BPSD).MethodBrain tissue previously fixed with 4% paraformaldehyde from 7 patients with different stages of AD were examined in this study. Sections were blocked with 0.2% IgG free albumin and the primary antibody (Table 1) was incubated overnight. Secondary antibody HRP was incubated considering the specie and isotype. Finally, the reaction was revealed with 0.0006% 3´3´diaminobenzidine and 0.006% H2O2 ResultThe cases with early stages of AD are morphologically characterized by diffuse and granular deposits of tau aggregate in a non‐fibrillar state in the transentorhinal region of the hippocampus and to a lesser extent in the cingulate cortex. Following this pattern, in cases with mild stage was found in less proportion extracellular NFT (E‐NFT) in CA1 region of the hippocampus, in contrast, there was a major labelling for this antibody in the cingulate cortex but for intracellular NFT. Finally, in moderate AD cases was found E‐NFT both in the cingulate cortex and hippocampus, being the latter where it was observed to a greater extent.ConclusionThere is a direct relationship in the processes of NFT formation and subsequent disease progression between the cingulate cortex and the hippocampus, having its origin in the latter.