Aspects of Neural Development
Some landmarks of neural development include the birth and differentiation of neurons from stem cell precursors, the migration of immature neurons from their birthplaces in the embryo to their final positions, outgrowth of axons and dendrites from neurons, guidance of the motile growth cone through the embryo towards postsynaptic partners, the generation of synapses between these axons and their postsynaptic partners, and finally the lifelong changes in synapses, which are thought to underlie learning and memory.
Typically, these neurodevelopmental processes can be broadly divided into two classes: activity-independent mechanisms and activity-dependent mechanisms. Activity-independent mechanisms are generally believed to occur as hardwired processes determined by genetic programs played out within individual neurons. These include differentiation, migration and axon guidance to their initial target areas. These processes are thought of as being independent of neural activity and sensory experience. Once axons reach their target areas, activity-dependent mechanisms come into play. Although synapse formation is an activity-independent event, modification of synapses and synapse elimination requires neural activity.
Developmental neuroscience uses a variety of animal models including mice Mus musculus, the fruit fly Drosophila melanogaster, the zebrafish Danio rerio, Xenopus laevis tadpoles and the worm Caenorhabditis elegans, among others.
Read more about this topic: Development Of Nervous System
Famous quotes containing the words aspects of, aspects and/or development:
“All the aspects of this desert are beautiful, whether you behold it in fair weather or foul, or when the sun is just breaking out after a storm, and shining on its moist surface in the distance, it is so white, and pure, and level, and each slight inequality and track is so distinctly revealed; and when your eyes slide off this, they fall on the ocean.”
—Henry David Thoreau (1817–1862)
“I suppose an entire cabinet of shells would be an expression of the whole human mind; a Flora of the whole globe would be so likewise, or a history of beasts; or a painting of all the aspects of the clouds. Everything is significant.”
—Ralph Waldo Emerson (1803–1882)
“Theories of child development and guidelines for parents are not cast in stone. They are constantly changing and adapting to new information and new pressures. There is no “right” way, just as there are no magic incantations that will always painlessly resolve a child’s problems.”
—Lawrence Kutner (20th century)