Morphogenesis of the cerebral ventricles during X. laevis development at stages 38-53, visualised by Qdot565 nanocrystals. The injection into the fourth cerebral ventricle of anesthetised embryos labelled the fourth cerebral ventricle almost exclusively in stage 38 (a) and stage 43 (b) embryos. The third cerebral ventricle (III) forms an oval shape by stage 43, and the midbrain ventricle (M) is visible between the fourth and third ventricles by stage 46. The lateral ventricles (L) bud off the third ventricle at stages 46 to 48 (c, d). All ventricles can be recognised clearly at stage 50 (bright-field; e, fluorescence; f). The morphology of the ventricles in stage 53 larvae is different from those of early larval stages (g). The central canal of the spinal cord is also labelled (h). All panels are dorsal views with anterior at the top. Scale bars, 1 mm. ca: cerebral aqueduct.