[Neurulation and interkinetic nuclear migration in the chick embryo (author's transl)].

Neurulation and interkinetic nuclear migration was studied in cells of the forming neural tube of chick embryos submitted to a variety of treatments. Our results show that cytochalasin B (5 mug/ml) does not protect microtubules against disruption occurring after 3 h at 2 degrees C nor does it prevent their repolymerization once they are cold-disrupted. However, db-cAMP protects microtubules against such cold disruption. We indicate that the inhibitory effect of cytochalasin B on interkinetic nuclear migration cannot be ascribed to an effect on microtubules.