PSY290H1 Chapter Notes - Chapter 9: Embryonic Stem Cell, Neural Plate, Neural Development
Document Summary
Brain is plastic; it continuously changes in response to its genetic programs and environment. A fertilized egg is totipotent (the cell can develop into any class of cell), then they become pluripotent, then multipotent (can develop into different cells of one class) and finally unipotent (can develop into only one type). The five phases of neurodevelopment are: introduction of the neural plate. There are three layers of embryonic cells, from outermost to innermost, they are: ectoderm, mesoderm and endoderm. Neural plate is a small patch of ectodermal tissue on the dorsal surface of the embryo and it"s the tissue that eventually becomes the human nervous system. The development of the neural plate is induced by chemical signals from an area of the underlying mesoderm (aka organizer). The cells of the neural plate are also called embryonic stem cells. Stem cells are cells that 1) have almost unlimited capacity to replicate themselves and 2) are toti/pluri/multipotent.