part of develops from composed primarily of immediate transformation of produces glial cell spondin-1 cell layer neural tube notochord floor plate http://upload.wikimedia.org/wikipedia/commons/8/89/Gray642.png FP Organizing center consisting of a small group of cells located at the ventral midline of the neural tube that influences the development of the nervous system, governing the specification of neuronal cell types and directing axonal trajectories.[AAO] AAO:0011041 ZFA:0000022 uberon The specialized glial structure (non-neuronal cells) situated at the ventral midline of the embryonic neural tube; this structure spans the anteroposterior axis from the midbrain to the tail regions, separating the left and right basal plates of the developing neural tube, and serves as an organizer to ventralize tissues in the embryo as well as to guide neuronal positioning and differentiation along the dorsoventral axis of the neural tube. EFO:0003473 TAO:0000022 BTO:0001720 ventral plate UBERON:0003079 "A structure integral to the developing nervous system of vertebrate organisms. Located on the ventral midline of the embryonic neural tube, the floor plate is a specialized glial structure that spans the anteroposterior axis from the midbrain to the tail regions. It has been shown that the floor plate is conserved among vertebrates with homologous structures in invertebrates such as the fruit fly Drosophila and the nematode C. elegans. Functionally, the structure serves as an organizer to ventralize tissues in the embryo as well as to guide neuronal positioning and differentiation along the dorsoventral axis of the neural tube." although this is classically defined as being located on the neural tube, in many AOs the floor plate continues post-embryonically after the neural tube has ceased to exist. Consider 'floor plate of neural tube'. bodenplatte Wikipedia:Floor_plate RETIRED_EHDAA2:0000545 EMAPA:32684 floorplate ectoderm-derived structure embryonic tissue presumptive floor plate