RT info:eu-repo/semantics/article
T1 Disruption o proteoglycans in neural tube fluid by B-
A1 Gato Casado, Ángel Luis
A1 Alonso Revuelta, María Isabel
A1 Moro Balbás, José Antonio
A1 Barbosa Ayucar, Enrique
K1 Neuroanatomia
K1 Embriología
AB Following neurulation, the  anterior end  of the  neural tube undergoes a dramatic increase in size due mainly to the  enlarging of the brain cavity. This cavity is filled with so-called neural tube fluid (NTF), whose positive pressure has been  shown to play  a key  role  in brain morphogenesis. This  fluid  contains a  water-soluble matrix, rich  in  chondroitin sulfate (CS),  which  has  been proposed as an osmotic regulator of NTF pressure genesis. The purpose of the present study is to observe the  influence of CS on NTF  osmolality and  its relation to NTF hydrostatic pressure and  brain expansion.NTF was obtained by means of microaspiration from the mesencephalic cavity of chick embryos. The osmolality of NTF between H.H. stages 20 and 29 was measured on the  basis of its cryoscopic point. CS synthesis was disrupted by  using 13-D-xyloside  and   the  induced variations in  brain volume were measured by means of morphometry. We also measured the variations in NTF osmolality, hydrostatic pressure, and  the  concentration of CS  and  sodium induced by means of 13-D-xyloside.Our  data reveal that, at the  earliest stages of development analyzed, variations in  NTF  osmolality show  a characteristic pattern that coincides with the  developmental changes in the  previously described fluid pressure.Chick  embryos treated with 13-D-xyloside, a chemical that disrupts CS synthesis, displayed a notable increase in brain volume but no other apparent developmental alterations. Morphometric analysis revealed that this increase was  due  to  hyperenlargement of the  brain cavity. 13-D-xyloside  brings about specific  changes in the  biochemical composition of NTF,  which  entails a large increase in CS concentration, mainly in the  form  of free  chains, and  in that of sodium. As a result, the  fluid’s osmolality and  brain intraluminal pressure increased, which could account for the increase in size of the brain anlage.These data  support the   hypothesis that  the   intraluminal  pressure involved in  embryonic brain enlargement  is  directly dependent on  NTF osmolality, and  that the  concentrations of CS and  its  associated microions could  play  a key role  in the  regulation of this process. Anat. Rec. 252:499–508, 1998. 	© 1998  Wiley-Liss, Inc.
PB Wiley-Liss
SN 1552-4914
YR 1998
FD 1998
LK http://uvadoc.uva.es/handle/10324/4486
UL http://uvadoc.uva.es/handle/10324/4486
LA eng
NO The Anatomical Record, 1998, 252, p.499-508
NO Producción Científica
DS UVaDOC
RD 23-nov-2024