Neurofibrillary tangles are an intra cellular abnormality, involving the cytoplasm of nerve cells.
Apple green birefringence of Congo red-stained tangle In Alzheimer's disease, neurofibrillary tangles are generally found in the neurons of the cerebral cortex and are most common in the temporal lobe structures, such as the hippocampus and amygdala. Silver-stained tangle in cerebral cortex 7. Variable amounts of other proteins can also be found attached to the abnormally-phosphorylated tau protein of the neurofibrillary tangles.