EFFECTS OF LIFELONG ETHANOL-CONSUMPTION ON CEREBELLAR LAYER VOLUMES IN AA AND ANA RATS

Aging and chronic alcohol consumption can cause degenerative changes i n the cerebellar cortex, In this study, the effects of aging and lifel ong alcohol consumption on cerebellar cortical layer volumes (molecula r and granular) and also white matter layer volumes were studied in al cohol-preferring (AA) and nonpreferring (ANA) rats of both sexes, The ethanol-consuming animals (EtOH) had 12% (w/v) ethanol as the only ava ilable fluid from 4 to 22 months of age, whereas the young (3 month) a nd old controls (24 months) had only water to drink. The volumes of mo lecular, granular, and white matter layers of the cerebellar vermis in folia II, IV, VII, and X were measured by using systematic sampling a nd a point-counting method. The volumes of the granular and white matt er layers showed consistent increase between 3 and 24 months of age, w hereas the volume of the molecular layer remained unchanged with incre asing age, Individual ethanol intake was measured over a 1-week period at the beginning and at the end of chronic ethanol exposure. Signific ant (ANOVA, p = 0.000) sex difference was found in the drinking behavi or in both lines, with females consuming more alcohol than males (dail y ethanol consumption at 22 months of age 3.2 +/- 0.3 vs, 7.1 +/- 0.3 g/kg for AA males and females; 3.2 +/- 0.3 vs. 5.4 +/- 0.4 g/kg for AN A males and females, respectively). The only ethanol-induced effect on the cerebellum was observed in ANA-EtOH females with a 15% reduction in the volumes of the molecular and granular layer in folium II compar ed with age-matched controls and a significant (p < 0.05, analysis of covariance with ethanol intake as a covariate) line difference in foli um II (molecular and granular layers) was observed between ANA-EtOH fe males and AA-EtOH females. Furthermore, the volume of the molecular la yer in folium II was significantly (p < 0.05, analysis of covariance w ith ethanol intake and body weights as covariates) reduced for ANA-EtO H females, compared with ANA-EtOH males indicating a sex difference in the cerebellar degeneration due to chronic alcohol consumption, Of th e three layers studied, the white matter layer was the most resistant layer to the effects caused by chronic alcohol consumption. In view of the fact that AA and ANA rats of both sexes differ regarding the drin king behavior and ethanol metabolism, they provide an important model for further research on ethanol-induced pathological changes in the ce ntral nervous system.