Calcium and neurulation in mammalian embryos.

The role of calcium in neurulation in rat embryos has been studied. Rat embryos at 10 X 4 days of gestation, when the cephalic neural folds have elevated but not fused, have been cultured in various media, and the effects of these media on the morphology of the cephalic neural folds have been observed by scanning and transmission electron microscopy. Embryos cultured in serum containing EDTA or EGTA, or in saline without divalent cations exhibit opening, then folding back ('collapse') of the cephalic neural folds. The neural cells lose their elongated shape and become rounded. Older embryos in which the cephalic neural folds have already fused do not show collapse of the neural tube. Culture of 10 X 4-day rat embryos with elevated but unfused cephalic neural folds in calcium- and magnesium-free saline to which either calcium or magnesium has been restored shows that calcium is the divalent cation which is essential for the maintenance of the elevated neural folds. In the presence of calcium, lanthanum, which competes for calcium sites, causes opening but not collapse of the elevated cephalic neural folds. Embryos treated with trypsin show dissociation of the lateral (non-neural) ectoderm but the neural folds remain elevated. If embryos in which the cephalic neural folds have been caused to collapse are further cultured in serum the folds re-elevate, although normal neural tube morphology is not completely regained. The possible implications of these observations to the understanding of the cellular mechanisms of normal neurulation, and of neural tube malformations are discussed.

[1]  M. Stanisstreet,et al.  Calcium and neurulation in mammalian embryos. II. Effects of cytoskeletal inhibitors and calcium antagonists on the neural folds of rat embryos. , 1986, Journal of embryology and experimental morphology.

[2]  M. Stanisstreet,et al.  Scanning electron microscopy of wound healing in rat embryos. , 1984, Journal of embryology and experimental morphology.

[3]  M. Stanisstreet,et al.  Calcium, microfilaments and morphogenesis. , 1983, Life sciences.

[4]  P. Hepler,et al.  Calcium antagonists and calmodulin inhibitors block cytokinin-induced bud formation in Funaria. , 1983, Developmental biology.

[5]  F. Beck,et al.  Growth of 9.5-day rat embryos in human serum. , 1983, Journal of embryology and experimental morphology.

[6]  R. Tsien,et al.  Mechanism of calcium channel blockade by verapamil, D600, diltiazem and nitrendipine in single dialysed heart cells , 1983, Nature.

[7]  R. Brun,et al.  Neurulation in the Mexican salamander (Ambystoma mexicanum): a drug study and cell shape analysis of the epidermis and the neural plate. , 1983, Journal of embryology and experimental morphology.

[8]  R. Nagele,et al.  Studies on the mechanisms of neurulation in the chick: possible involvement of myosin in elevation of neural folds. , 1983, The Journal of experimental zoology.

[9]  A. Read,et al.  Apparent prevention of neural tube defects by periconceptional vitamin supplementation. , 1981, Archives of disease in childhood.

[10]  G. Morriss-Kay.  Growth and development of pattern in the cranial neural epithelium of rat embryos during neurulation. , 1981, Journal of embryology and experimental morphology.

[11]  S. Fabro,et al.  Quantitation of rat embryonic development in vitro: a morphological scoring system. , 1981, Teratology.

[12]  P. Alberch,et al.  The mechanical basis of morphogenesis. I. Epithelial folding and invagination. , 1981, Developmental biology.

[13]  R. Nagele,et al.  Diazepam-induced neural tube closure defects in explanted early chick embryos. , 1981, Teratology.

[14]  D. Witiak,et al.  Effect of three calcium antagonists on platelet secretion and metabolism. , 1981, Biochemical pharmacology.

[15]  M. S. Steinberg,et al.  Two distinct adhesion mechanisms in embryonic neural retina cells. II. An immunological analysis. , 1981, Developmental biology.

[16]  M. S. Steinberg,et al.  Two distinct adhesion mechanisms in embryonic neural retina cells. I. A kinetic analysis. , 1981, Developmental biology.

[17]  M. Kaufman,et al.  Neural tube closure defects following in vitro exposure of mouse embryos to xylocaine. , 1980, The Journal of experimental zoology.

[18]  R. Strohman,et al.  Diazepam induces relaxation of chick embryo muscle fibers in vitro and inhibits myosin synthesis. , 1979, Experimental cell research.

[19]  R. Nagele,et al.  Neural tube closure defects caused by papaverine in explanted early chick embryos. , 1979, Teratology.

[20]  R. Strohman,et al.  Diazepam inhibits myoblast fusion and expression of muscle specific protein synthesis. , 1978, Science.

[21]  D A New,et al.  WHOLE‐EMBRYO CULTURE AND THE STUDY OF MAMMALIAN EMBRYOS DURING ORGANOGENESIS , 1978, Biological reviews of the Cambridge Philosophical Society.

[22]  J. Geelen,et al.  Closure of the neural tube in the cephalic region of the mouse embryo , 1977, The Anatomical record.

[23]  R. Rice,et al.  A scanning electron microscopic and x-ray microanalytic study of cell surface material during amphibian neurulation. , 1977, The Journal of experimental zoology.

[24]  S. E. Hitchcock,et al.  Regulation of motility in nonmuscle cells , 1977, The Journal of cell biology.

[25]  D. Moran.  A scanning electron microscopic and flame spectrometry study on the role of Ca2+ in amphibian neurulation using papaverine inhibition and ionophore induction of morphogenetic movement. , 1976, The Journal of experimental zoology.

[26]  R. Feinman,et al.  Inhibition of platelet secretion by an antagonist of intracellular calcium. , 1976, Biochemical and biophysical research communications.

[27]  D. Cockroft,et al.  Improved development of head-fold rat embryos in culture resulting from low oxygen and modifications of the culture serum , 1976 .

[28]  R. Rice,et al.  Action of papaverine and ionophore A23187 on neurulation , 1976, Nature.

[29]  M. Perry.  Microfilaments in the external surface layer of the early amphibian embryo. , 1975, Journal of embryology and experimental morphology.

[30]  M. H. Malagodi,et al.  Pharmacological evaluation of a new Ca2+ antagonist, 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate hydrochloride (TMB-8): studies in smooth muscles. , 1974, European journal of pharmacology.

[31]  George B. Weiss,et al.  CELLULAR PHARMACOLOGY OF LANTHANUM , 1974 .

[32]  D. New,et al.  Culture of explanted rat embryos in rotating tubes. , 1973, Journal of reproduction and fertility.

[33]  H. Huxley,et al.  Muscular Contraction and Cell Motility , 1973, Nature.

[34]  H. Lardy,et al.  A23187: a divalent cation ionophore. , 1972, The Journal of biological chemistry.

[35]  P Karfunkel,et al.  The activity of microtubules and microfilaments in neurulation in the chick. , 1972, The Journal of experimental zoology.

[36]  B. Burnside,et al.  Microtubules and microfilaments in newt neuralation. , 1971, Developmental biology.

[37]  P. Karfunkel,et al.  The role of microtubules and microfilaments in neurulation in Xenopus. , 1971, Developmental biology.

[38]  M. Handel,et al.  Cell shape and morphology of the neural tube: implications for microtubule function. , 1971, Developmental biology.

[39]  T. E. Schroeder,et al.  Neurulation in Xenopus laevis. An analysis and model based upon light and electron microscopy. , 1970, Journal of embryology and experimental morphology.

[40]  S. Imai,et al.  Actions of calcium and certain multivalent cations on potassium contracture of guinea‐pig's taenia coli , 1967, The Journal of physiology.

[41]  T. E. Schroeder,et al.  Cytoplasmic filaments and morphogenetic movement in the amphibian neural tube. , 1967, Developmental biology.

[42]  C. Waddington,et al.  A note on the mechanisms of cell deformation in the neural folds of the Amphibia. , 1966, Experimental cell research.

[43]  V. Ferm,et al.  Colchicine Teratogenesis in Hamster Embryos.∗ , 1963, Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine.

[44]  K. O'shea.  Calcium and neural tube closure defects: an in vitro study. , 1982, Birth defects original article series.

[45]  D. Beebe,et al.  Lens epithelial cell elongation in the absence of microtubules: evidence for a new effect of colchicine. , 1979, Science.

[46]  T. E. Schroeder.  Cytochalasin B, cytokinesis, and the contractile ring. , 1978, Frontiers of biology.

[47]  A. Fleckenstein.  Specific pharmacology of calcium in myocardium, cardiac pacemakers, and vascular smooth muscle. , 1977, Annual review of pharmacology and toxicology.

[48]  P Karfunkel,et al.  The mechanisms of neural tube formation. , 1974, International review of cytology.

[49]  H. Rasmussen,et al.  The role of cyclic AMP and calcium in cell activation. , 1972, CRC critical reviews in biochemistry.

[50]  M. Karnovsky,et al.  A formaldehyde-glutaraldehyde fixative of high osmolality for use in electron-microscopy , 1965 .