BIO380H5 Lecture Notes - Lecture 9: Progenitor Cell, Anencephaly, Hypothalamus
Document Summary
A early development: anterior part of isthmic organizer expresses otx-2 and posterior part expresses gbx-2 (in the neural tube, isthmic orgaizer will divide the midbrain and forebrain from the hindbrain. Telencephalon, to make it distinct: telencephalon, under the influence of other fgf-8 from the anterior neural ridge and also. Age of 3 weeks: only the neural tube present. Age of 4 weeks: 4 parts of cns, 3 parts of brain. Age of 5 weeks; 6 parts of cns. By the end of 6 weeks, all parts of the brain are differentiated (14 parts) Histogenesis within the central nervous system: proliferation within the neural tube, the neural tube become organized into a pseudostratified epithelium , the nuclei appear to be located in several separate layers within the elongated neuroepithelial cells. The nuclei undertake extensive shifts of position within the cytoplasm of the neuroepithelial cells: dna synthesis occurs in nuclei located near the external limiting membrane.
