Morphological changes in the cerebellum as a result of ethanol treatment and cigarette smoke exposure: A study on astrogliosis, apoptosis and Purkinje cells

The link between Ethanol (EtOH) and tobacco (TOB) has potentially important implications for people involved in alcohol treatment; many alcoholics smoke, putting them at high risk of tobacco-related complications. The present study investigates the effect of chronic exposure to cigarette smoke, EtOH consumption and the combination of both on astrogliosis and apoptosis in the cerebellum of rats. Adult male Wistar rats were divided into 4 groups (8 animals per group): vehicle (glucose 3%, 10 mL/kg, twice a day), EtOH treated (EtOH 2 g/kg, twice a day), exposure to cigarette smoke (TOB, smoke of 6 cigarettes, twice a day) and a combination of EtOH and cigarette smoke (TOB + EtOH, twice a day). The treatment period was 57 days, after which the animals were euthanized, the cerebellum removed and subjected to immunohistochemical studies focusing on glial fibrillary acidic protein (GFAP), cleaved caspase-3, and S100. We also counted the number of Purkinje cells (PC) present following treatment. The combination of both EtOH and TOB exposure induced an increase in GFAP immunoreactivity, whilst TOB alone increased apoptosis in the white matter of the cerebellum. In addition, EtOH consumption reduced the number of PC and TOB tempered this effect. Overall, the present study opens up relevant perspectives for the consequences on human health of the combined use of alcohol and smoking, by demonstrating the biological mechanisms and cerebellar function vulnerabilities to combined use and dependence of licit drugs.