Document Detail


Histological and ultrastructural studies of secondary neurulation in mouse embryos.
MedLine Citation:
PMID:  6731331     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The histological and ultrastructural features of secondary neurulation in C57BL/6 mouse embryos were examined as a first step in the analysis of how this process occurs in mammalian embryos. Secondary neurulation involves two major events in mouse embryos: (1) formation of the medullary rosette (9.5- to 10-day embryos) or plate (11- to 12-day embryos), and (2) cavitation. These two events occur simultaneously. The medullary rosette consists of elongated tail bud cells, radially arranged around a central lumen formed by cavitation. The secondary portion of the neural tube forms in 9.5- to 10-day embryos by progressive enlargement of the central lumen and addition (by cell recruitment or mitosis) of tail bud cells to the rosette. The medullary plate likewise consists of elongated tail bud cells, but these cells do not surround a central cavity. Instead, cells of the medullary plate extend ventrad from the basal aspect of the dorsal surface ectoderm to a slit-like cavity formed by cavitation. Formation of the secondary neural tube occurs in 11- to 12-day embryos, principally by the recruitment of more lateral and ventral tail bud cells into the medullary plate. Free cells and cellular debris are frequently encountered in the forming lumen of the secondary neural tube, but cells exhibiting signs of necrosis were absent in cavitating regions. Numerous small intercellular junctions form at the inner ( juxtaluminal ) ends of tail bud cells as the medullary rosette or plate is forming and cavitation is occurring. These observations suggest that cavitation per se (i.e., formation of a lumen) during secondary neurulation is a relatively passive phenomenon, which results principally from neighboring cells becoming polarized apicobasally and incorporated into a primitive neuroepithelium. The latter constitutes the walls of the forming secondary neural tube.
Authors:
G C Schoenwolf
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of anatomy     Volume:  169     ISSN:  0002-9106     ISO Abbreviation:  Am. J. Anat.     Publication Date:  1984 Apr 
Date Detail:
Created Date:  1984-07-12     Completed Date:  1984-07-12     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0376312     Medline TA:  Am J Anat     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  361-76     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Central Nervous System / embryology*
Gestational Age
Mice / embryology*
Mice, Inbred C57BL
Microscopy, Electron
Microscopy, Electron, Scanning
Grant Support
ID/Acronym/Agency:
HD 15231/HD/NICHD NIH HHS; HD 18143/HD/NICHD NIH HHS; NS 18112/NS/NINDS NIH HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Göteborg Metoprolol Trial: mortality and causes of death.
Next Document:  Arterial anatomy of chicken embryo and hatchling.