The mechanisms by which the genotype influences the neuropharmacological and behavioral effects of alcohol use remain only poorly understood. These investigations explore the relationships between genotype and the neuropharmacological and behavioral effects of ethanol in a series of inbred strains of mice. These investigations concentrate (although not exclusively) on serotonergic, adrenergic and GABAergic systems since these have been strongly implicated in the neuropharmacological effects of ethanol. Differences in levels of neurotransmitters, their metabolites and the metabolizing enzymes are assessed by radioligand binding techniques. Genetic variation in behavior is asses using established tests of locomotion, exploration, anxiety and aggression. A greater understanding of these relationships lead to fuller appreciation of the mechanisms by which genes influence alcohol-related behaviors.