Determination of the age-related changes in the rat cerebellar cortex by using histologic and histometric methods

Aging is characterized as a process resulting in the structural and functional deterioration of several essential organs and tissues. This study aimed to determine the effects of normal aging on the cerebellum by using histological and histometric techniques. A total of 24 male Wistar albino rats were divided into three groups: young (4-6 weeks), adult (20-22 weeks), and old (22-24 months). Cerebellar tissue samples were treated using histological and immunohistochemical techniques. The slides were evaluated using a light microscope. Molecular layer thickness was high in the adult group compared to the younger and older groups, whereas the granular layer was significantly thicker in both the adult and elderly groups than in the young rat group (P < 0.05). The total cortical thickness exhibited statistically significant differences among all age groups. The thickest cortex was observed in the adult group (P < 0.05). PAS-positive aging pigment granules were observed in the cytoplasm of Purkinje cells in older rat groups. The density of glial fibrillary acidic protein-immunoreactive (GFAP-IR) astrocytes in old rats was significantly increased compared to young and adult rats with distinct hypertrophy and strong GFAP immunoreactivity in astrocyte cell bodies. It was established that, despite age-related variations that exist, cerebellar folia height and width gradually increased from young to adult rat. In contrast, old rats have decreased cerebellar folia height and width than adults.