MORPHOLOGICAL CHARACTERISTICS OF VENTRAL HIPPOCAMPUS OF AGING RATS WITH SPECIAL REFERENCE TO THE EXPRESSION OF INDUCIBLE AND ENDOTHELIAL NO-SYNTHASE

Abstract

Structural changes in CA1 and CA3 areas of ventral hippocampus were studied in 12- and 24-month-old rats (n = 20). Paraffin sections of the brain were stained by Nissl’s method, and the proportion of shrunken neurons with hyperchromatic cytoplasm was calculated. Changes of inducible and endothelial NO-synthases (iNOS, eNOS) expression were registered. In old (24 months) rats, most pronounced signs of neuronal damage were observed in the hippocampal CA3 pyramidal layer. The proportion of shrunken neurons with hyperchromatic cytoplasm was increased, while the relative density of neurons was decreased. The neurons demonstrated the pericellular edema and vacuolization of cytoplasm. The increased expression of iNOS was detected in the neurons of CA3 pyramidal layer while eNOS expression in CA1 and CA3 was decreased both in neurons and endothelial cells of microcirculatory bed vessels as compared to that in young (12 months) animals.

Keywords

iNOS / eNOS / hippocampus / neurons / aging / iNOS / eNOS

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