Given the evolutionary conservation of genes and pathways affecting key biological processes between vertebrates, invertebrates and humans, studies on model organisms (rats, mice, flies and nematodes) have played an important role in identifying potential candidate genes that contribute to alcohol intoxication. Invertebrate and vertebrate models show similar symptoms of alcohol intoxication, including loss of postural control, sedation, immobility and development of tolerance. After alcohol intoxication, mice and rats increase their alcohol consumption, develop tolerance and even alcohol dependence. Drosophila develops tolerance after a single exposure to ethanol [42]. In addition to rapid tolerance, flies develop chronic tolerance after prolonged exposure to a low concentration of ethanol [43]. Caenorhabditis elegans also exhibits tolerance after continuous ethanol exposure [44] and develops ethanol preference as a result of prolonged pre-exposure [45].
