In the developing vertebrate, the neural tube is the embryo's precursor to the central nervous system, which comprises the brain and spinal cord. The neural groove gradually deepens as the neural folds become elevated, and ultimately the folds meet and coalesce in the middle line and convert the groove into a closed tube, the neural tube or neural canal (which strictly speaking is the center of the neural tube), the ectodermal wall of which forms the rudiment of the nervous system. [WP,unvetted].

http://upload.wikimedia.org/wikipedia/commons/6/64/Gray19_with_color.png

The mature structure of the neural tube exists when the tube has been segmented into the forebrain, midbrain, hindbrain and spinal cord regions. In addition neural crest has budded away from the epithelium

The dorsal tubular structure in the vertebrate embryo that develops into the brain and spinal cord. [TFD][VHOG], Hollow epithelial tube on dorsal side of the embryo that develops into the central nervous system.[AAO]

uberon

presumptive central nervous system, neural primordium, tubus neuralis

(...) at some stage of its development, every chordate exhibits five uniquely derived characters or synapomorphies of the group: (...) (4) a single, tubular nerve cord that is located dorsal to the notochord (...).[well established][VHOG]

UBERON:0001049

http://purl.obolibrary.org/obo/uberon.owl, http://purl.obolibrary.org/obo/cl.owl

• neural tube lumen

• neural tube development

• neural tube formation

• future spinal cord

• germinal neuroepithelium

• notochord

• neural tube lumen
• anterior neural tube
• posterior neural tube
• germinal neuroepithelium
• neural tube marginal layer
• neural tube ventricular layer
• neural tube mantle layer