Abstract: | The effect of antagonists of biogenous amines (antitransmitters--AT) and colchicine on rapid morphogenetic processes in the explants of embryonic ectoderm with underlying mesoderm cut from the lateral region of Rana temporaria embryos at the late neurula-early taibud stages was studied. The normal morphogenesis of the explants consists of two successive phases: phase of contact polarization and phase of cell movement into the fragment. The high concentrations of AT inhibited completely the morphogenesis of explants but somewhat lower concentrations inhibited the second phase of morphogenesis and not only did not prevent the cell polarization but even assisted its propagation over all the fragment. The inhibiting effect of AT was relieved by 5-hydroxytryptamine which per se stimulated the morphogenesis of explants. Thus, AT exert a specific inhibition of the motility of embryonic cells but do not prevent the contact interactions responsible for cell polarization within every layer. |