The expansive force generated by the positive pressure of the neural tube fluid confined inside the brain vesicles has been shown to be a key factor during the earliest stages of brain morphogP.nesis and development of chick embryos. In a previous study,we demonstrated the existence of an intracavity extracellular matrix rich in condroitin sulfate in this species, which could be in volved in the regulation of the expa nsive process. In this report, scanning electron microscopy and immunohisto chemistry show that,after neurulation,a similar extracel lular matrix rich in chondroitin sulfate is present inside the brain vesicles of rat embryos during early enlarge ment of the brain anlage. In vitro treatment of rat embryos-
Abbreviations used in this paper
bryos with B-0-xyloside (a chemical compound which
