Morphological features of corpora amylacea in human parahippocampal cortex during aging

ABSTRACT

Introduction/Aim: Aging of the parahippocampal cortex is accompanied by atrophy. The most common changes include cell number reduction, formation of corpora amylacea in astrocytes, which may represent the basis for the development of cognitive dysfunction. The aim of this study was to detect presence and distribution of corpora amylacea in subpial and subcortical region of parahippocampal cortex during aging process using histochemical analysis as well as to carry out quantification of structural changes in different cortical layers using histochemical and immunohistochemical methods. Material and Methods: Material represents tissue of uncus of parahippocampal gyrus of right cerebral hemisphere of 30 cadavers taken from autopsies carried out at the Forensic Medicine Institute of the Niš Faculty of Medicine. Upon tissue preparation using standard histological procedures, 10 μm thick sections were made and stained with hematoxylin eosin and periodically with acid Schiff's method. The total number of 30 samples, 16 to 93 years of age, was analyzed. Results: During the normal aging process in parahippocampal cortex the number of corpora amylacea localized in subpial region increases, and it is even greater in subcortical white matter, with no significant change in size and shape. Positive reaction to neuron specific enolase, determined by immunohistochemical methods suggests the presence of neural components, while a weaker reaction to glial acid protein and positive one to S100 protein suggests the possibility that the corpora amylacea are astrocyte inclusion. Conclusion: The obtained results indicates that the presence of these structural changes may lead to damage of those brain structures responsible for normal memory function and thus responsible for cognitive changes present in healthy elderly individuals.