arsenic is an important environmental toxicant which is usually found in drinking water in inorganic form. the hypothesis tested in this investigation is; arsenic exposure causes neural tube defects (ntds) andthese defects of the central nervous system are more likely related to folate deficiency during fetal life. in this study, sodium arsenate was administered via intraperitoneal route at a r...

During the emergence of neural crest cells from the neural tube, the expression of cadherins dynamically changes. In the chicken embryo, the early neural tube expresses two cadherins, N-cadherin and cadherin-6B (cad6B), in the dorsal-most region where neural crest cells are generated. The expression of these two cadherins is, however, downregulated in the neural crest cells migrating from the n...

Pax-3 is a transcription factor that is expressed in the neural tube, neural crest, and dermomyotome. We previously showed that apoptosis is associated with neural tube defects (NTDs) in Pax-3-deficient Splotch (Sp/Sp) embryos. Here we show that p53 deficiency, caused by germ-line mutation or by pifithrin-alpha, an inhibitor of p53-dependent apoptosis, rescues not only apoptosis, but also NTDs,...

Neurovascular development requires communication between two developing organs, the neuroepithelium and embryonic blood vessels. We investigated the role of VEGF-A signaling in the embryonic crosstalk required for ingression of angiogenic vessel sprouts into the developing neural tube. As the neural tube develops, blood vessels enter at specific points medially and ventrally from the surroundin...

Both neurons and glia of the PNS are derived from the neural crest. In this study, we have examined the potential function of lunatic fringe in neural tube and trunk neural crest development by gain-of-function analysis during early stages of nervous system formation. Normally lunatic fringe is expressed in three broad bands within the neural tube, and is most prominent in the dorsal neural tub...

The differentiation of neural crest cells from progenitors located in the dorsal neural tube appears to involve three sequential steps: the specification of premigratory neural crest cell fate, the delamination of these cells from the neural epithelium and the migration of neural crest cells in the periphery. BMP signaling has been implicated in the specification of neural crest cell fate but t...

Neural tube closure is a critical morphogenetic event that is regulated by dynamic changes in cell shape and behavior. Although previous studies have uncovered a central role for the non-canonical Wnt signaling pathway in neural tube closure, the underlying mechanism remains poorly resolved. Here, we show that the missing in metastasis (MIM; Mtss1) protein, previously identified as a Hedgehog r...

The avian spinal cord is characterized by an absence of motor nerves and sensory nerves and ganglia at its caudalmost part. Since peripheral sensory neurons derive from neural crest cells, three basic mechanisms could account for this feature: (i) the caudalmost neural tube does not generate any neural crest cells; (ii) neural crest cells originating from the caudal part of the neural tube cann...

Closure of the neural tube during embryogenesis is a crucial step in development of the central nervous system. Failure of this process results in neural tube defects, including spina bifida and anencephaly, which are among the most common birth defects worldwide. Maternal use of folic acid supplements reduces risk of neural tube defects but a proportion of cases are not preventable. Folic acid...

the effect and arrangement of cytoskeleton (microtubules, microfilaments and neurofilaments) in neurulation of chick embryo examined by immunoperoxidase method from stage 6 to stage 12. the results were as follows: 1) microtubules aggregated in the perinuclear region from which they radiated to take longitudinal course beneath the membrane. 2) microfilaments were aggregated in the apical ends (...