( 1 ) a pronounced anteroposterior patterning appeared during neuroectodermal development , such that the long-chain unbranched and long-chain branched sequences , which were abundant on the ectoderm of the earlier stages , were replaced by short-chain branched sialo-oligosaccharides in the developing brain and anterior neural tube .
C1518271
neuroectodermal
C0231024
neural