Postulated mechanisms underlying the development of neural tube defects. Insights from in vitro and in vivo studies.

In recent years, use of animal models has resulted in acquisition of a significant amount of new information regarding normal and abnormal neural tube development. Studies of mutant and of teratogen-exposed mice are complementary, with each providing insights that promise to advance our understanding of the other. Analysis of teratogen-exposed embryos is best suited for identifying susceptible developmental stages and vulnerable populations. Advances in molecular genetics, with the ability to identify gene products, their cell/tissue location, and, potentially, to understand their function, will make naturally occurring as well as man-made mutants invaluable for understanding the heterogeneous mechanisms that underly NTDs.