Experiments on ß-mercaptoethanol as an inhibitor of neurulation movements in amphibian larvae
The morphogenetic movements of the ectoderm during neurulation include: (1) the movements taking place within the neural plate, which becomes longer and more concentrated in a medio-lateral direction (Jacobson, 1962); and (2) those found in the lateral epidermis layer which, in an epibolic way, moves in a dorsal direction, thus exerting a pushing effect on the lateral edges of the neural plate (Lewis, 1947). The former is, to a great extent, realized by a change of form of the neuroepithelium cells, from cuboidal in early neurulae to the high columnar cells observed during later phases of neural-tube closure. In the epidermis, on the other hand, the case is the reverse. The dorsal spreading of the layer is made possible by a flattening of the cells. In a series of papers, Brachet and his group have show that β-mercaptoethanol (HSCH2·CH2OH; in this article, called ME) inhibits neurulation (for review, see Brachet, 1964).