Neurodevelopment During neurulation in vertebrate embryos, a topologically flat surface pinches off a tube to form the central nervous system. Deficiencies in folate can cause failure to close that tube, leading to birth defects such as spina bifida. Balashova et al. used the amphibian Xenopus laevis , in which neurulation is externally visible on developing embryos, to parse what goes wrong. The analysis points to a key role of folate receptor-a, found at the right time and place—at the apical surface of the neural plate—where it interacts with cytoskeletal and adherens junction components. The changes in tissue shape that signify neurulation follow from changes in the shape of the constituent cells: As cellular apices constrict, the tissue folds. Folate seems to function here not in its metabolic capacity, but as a signal modifying cellular shape. Development 10.1242/dev.137315 (2017).