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The dorsal nerve cord is an anatomical feature found in chordate animals, mainly in the subphyla Vertebrata and Cephalochordata, as well as in some hemichordates. It is one of the five embryonic features unique to all chordates, the other four being a notochord , a post-anal tail , an endostyle , and pharyngeal slits .
The evolution of nervous systems ... The fundamental bilaterian body form is a tube with a ... whereas in deuterostomes the nerve cord is on the dorsal (usually top ...
Alexander Kowalevsky first described the key anatomical features of the adult amphioxus (hollow dorsal nerve tube, endostyle, segmented body, postanal tail). [35] De Quatrefages first completely described the nervous system of amphioxus. [36] Other important contributions to amphioxus adult anatomy were given by Heinrich Rathke [37] and John ...
BMP from the dorsal end of the neural tube seems to act in the same concentration-dependent manner as Shh in the ventral end. [11] This was shown using zebrafish mutants that had varying amounts of BMP signaling activity. Researchers observed changes in dorsal-ventral patterning, for example, zebrafish deficient in certain BMPs showed a loss of ...
Acorn worms have a plexus concentrated into both dorsal and ventral nerve cords. The dorsal cord reaches into the proboscis, and is partially separated from the epidermis in that region. This part of the dorsal nerve cord is often hollow, and may well be homologous with the brain of vertebrates. [9]
A hollow dorsal nerve cord, also known as the neural tube, which develops into the spinal cord, the main communications trunk of the nervous system. In vertebrates, the rostral end of the neural tube enlarges into several vesicles during embryonic development, which give rise to the brain. Pharyngeal slits.
The neural patterning genes vnd, ind, msh, and netrin are expressed in the Drosophila ventral nerve cells and midline mesectoderm. The chordate homologs of these genes, NK2, Gsh1/2, Msx1/3, and Netrin, are expressed in the dorsal neural tube.
Beginning in the future neck region, the neural folds of this groove close to create the neural tube. The formation of the neural tube from the ectoderm is called neurulation. The ventral part of the neural tube is called the basal plate; the dorsal part is called the alar plate. The hollow interior is called the neural canal. By the end of the ...