Only embryos that displayed active heartbeats and blood circulation at the end of culture were used for analysis (>95% among all cultured embryos). We observed delayed growth and reduced overall growth of embryos treated with alcohol, in agreement with a previous report.52 Overall growth retardation was accompanied by significant alterations in development of the heart, caudal neural tube, brain vesicles, optic system and limb buds (Fig. 1). Developmental abnormalities in various organ systems (Fig. 1), including abnormalities of the heart and ventricular chambers, a reduced blood/vascular system, flattened forebrain, small/slanted eyes, abnormal tail morphology, abnormal limb web, and an unfinished turning of the neural axis were seen in the alcohol-treated embryos. Furthermore, approximately 33% of the alcohol-treated embryos had a neural tube opening abnormality compared to <5% of the controls. Failure of neural tube closure occurred most frequently in the head fold, although delayed or incomplete neural tube closure in midbrain and hindbrain was also seen. The abnormalities and developmental delays were clearly more severe in alcohol-treated embryos with neural tube opening (ALC-NTO) than in alcohol-treated embryos with neural tube closed (ALC-NTC) subgroups, particularly in development of the neural axis, including hindbrain, midbrain, forebrain and optic vesicle.
