BIO380H5 Lecture Notes - Lecture 19: Cauda Equina, Posterior Grey Column, Anterior Grey Column
Document Summary
Induction- primary induction by the notochord and second induction by the neural tissues. Proliferation- response of neuroectodermal cells to primary induction. Pattern formation- cell response to genetic and environmental cues. Determination- identitity of specific types of glial cells. Cell migration, differentiation, formation of synapses, stabilization/elimination of interneuronal connections, and development of patterns of neuronal function (reflex movements) Primary induction forms a thick ectodermal neural plate overlying the notochord. Dorsal cctoderm produces bmp-4 which inhibits it from forming the neural tissue. Noggin and chordin block bmp-4 and allow dorsal ectoderm - neural tissue/plate. Prechordal plate and visceral endoderm- txn factor otx-2 and gbx-2- boundary between these factors forms the isthmic organizer; fgf-8 and wnt-1 diffuses from this boundary and set up the mid and hindbrain. Hox genes- segmentation of hindbrain into rhombomeres-signals the organization of facial and cervical region. Closure of neural tube first in the region where somites occur. Unfused regions of neural tube are cranial and caudal neuropores.
