[Present status of behavioral teratology in Japan]

The thalidomide catastrophe in 1959-1962 has given great impetus to the basic research interests in the adverse effects of various insults on germ cells, embryos, fetuses, and immature postnatal individuals. It has called further attention to behavioral ability to learn or respond appropriately to a changing environment in the offspring that are prenatally exposed to various insults, even though the insults have negligible or no congenital malformations. The new field, behavioral teratology, obtained independence from its mother field teratology in the mid 1970s. The fact that most behavioral alterations can be traceable to adverse influences in the environment does not necessarily mean that it has given insight into the mechanism by which these behavioral deviations took place in developmental processes. Cause-and-effect relationships in behavioral teratogenicity are not always apparent, and thereby behavioral teratology retains distinctive methodological problems.