On the mechanism of morphological differentiation in the nervous system. I. The transformation of a neural plate into a neural tube

Autor: Otto C. Glaser
Rok vydání: 1914
Předmět:
Zdroj: The Anatomical Record. 8:525-551
ISSN: 1097-0185
0003-276X
DOI: 10.1002/ar.1090081204
Popis: The early development of the vertebrate nervous system is among the commonplaces of descriptive embryology. Every elementary text-book tells us that the first clearly recognizable rudiment is a flat patch of cells ectodermal in nature; how in due course of time after the appearance of a longitudinal furrow, the edges of this plate rise, meet in the mid-dorsal line, and fuse to form a tube, enclosing the neurocoel. What however are the forces at work when the primitive plate changes into a tube? This question was in the mind of His1 when he wrote his classic letters, ‘‘Unsere Korperform.” I n the fourth of these lucid epistles, His shows that the nervous system, during the period of folding, grows faster than the surrounding tissues with which it is continuous. On the assumption that these resist any increase in the width of the neural plate, he shows that the latter, must fold under the mechanical necessities of the case. Models, in which the entire process could be simulated at will, helped to emphasize the argument. The well-known experiments of ROUX,~ however, proved that this view of the origin of the neural groove is mechanically impossible, despite the inequalities of growth emphasized by His.
Databáze: OpenAIRE
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