There are a limited number of studies that have investigated ethanol-induced changes in expression of nAChRs and therefore it is certainly an area of research which should be expounded upon. In vitro experiments demonstrated nAChRs are directly affected by ethanol and after long-term exposure these receptors may undergo anatomical and functional changes, possibly by altering receptor expression or composition (Dohrman and Reiter, 2003). In M10 cells, ethanol modulates the number of nAChRs by initially blunting the expression during short exposure (6–72 h) but increasing it with longer incubation periods (96 h). Similar results were found with co-application of relatively high concentrations of nicotine (1 μM) and ethanol (100 mM); moreover, the elevated receptor expression after chronic exposure (96 h) remained up to 7 days following the removal of the drugs (Dohrman and Reiter, 2003). In a different study, long-term consumption of ethanol (5 months) by rats increased the levels of [3H]-nicotinic binding in the hypothalamus and thalamus, and decreased the levels in the hippocampus (Yoshida et al., 1982). In ethanol-treated (6 months) mice, small changes in [3H]-nicotinic binding were found
