2Singh I, Pal G P. Human Embryology[M]. Delhi: Mac- millan India LTD, 2001..33--59.
3Chenn A, McConnell, S K. Cleavage orientation and the asymmetric inheritance of Notchl immunoreactivity in mammalian neurogenesis[J]. Cell, 1995,82 (4) 631 -- 641.
4Monk C S, Webb S J, Nelson C A. Prenatal neurobiolo- gical development: molecular mechanisms and anatomical change[J]. Dev Neuropsychol, 2001, 19(2):211--236.
5Hugnot J P, Franzen R. The spinal cord ependymal re- gion a stem cell niche in the caudal central nervous sys- tem[J]. Front Biosci, 2011,1(6) :1 044--1 059.
6Chesnutt C, Burrus L W, Brown A M, et al. Coordinate regulation of neural tube patterning and proliferation by TGFt and WNT activity[J]. Dev Biol, 2004, 274 (2): 334--347.
7Li Q, Martin J H. Postnatal development of corticospinal axon terminal morphology in the cat[J]. Comp Neurol, 2001, 435(2) :127--14].
8Czeizel A E, Dudds I, Paput L, et al. Prevention of neu- ral-tube defects with perieoneeptional folic acid, methyl-folate, or multivitamins? I-J]. Ann Nutr Metab, 2011, 58(4) :263--271.
9Logan C V, Abdel-Hamed Z, Johnson CA. Molecular genetics and pathogenic mechanisms for the severe ciliopa- thies: insights into neurodevelopment and pathogenesis of neural tube defects [-J]. Mol Neurobiol, 2011, 43 (1) : 12--26.
10Looby S, Flanders A. Spine traumaEJ. Radiol Clin North Am, 2011, 49(1) :129--163.
