In animal models of prenatal alcohol exposure, sources of variability include the pattern, concentration, amount, and developmental stage of alcohol exposure, maternal stress, embryonic growth and maturation of embryos between litters and even within a given litter and within inbred strains of mice [29]. Control of all these variables in rapidly developing embryos is virtually unattainable in vivo. To limit these variables, a whole embryonic culture [30,31] was adopted, including stage alignment based on somite number, in which the pattern, amount and concentration of alcohol and embryonic staging were controlled. Inbred C57BL/6 mice, with known susceptibility to ethanol teratogenesis [32,33], were used for this study.
