Essential idea: Modification of neurons starts in the earliest stages of embryogenesis and continues to the final years of life.
This coloured Micrograph shows the development of the neural tube. At this early stage of development, the embryonic neural plate is still closing. Below the neural tube is the notochord, and at each side of the neural tube the mesoderm is organised to form the somites.
Understandings, applications and skills
|A.1.U1||The neural tube of embryonic chordates is formed by infolding of ectoderm followed by elongation of the tube. [Terminology relating to embryonic brain areas or nervous system divisions is not required.]|
|A.1.U2||Neurons are initially produced by differentiation in the neural tube.|
|A.1.U3||Immature neurons migrate to a final location.|
|A.1.U4||An axon grows from each immature neuron in response to chemical stimuli.|
|A.1.U5||Some axons extend beyond the neural tube to reach other parts of the body.|
|A.1.U6||A developing neuron forms multiple synapses.|
|A.1.U7||Synapses that are not used do not persist.|
|A.1.U8||Neural pruning involves the loss of unused neurons.|
|A.1.U9||The plasticity of the nervous system allows it to change with experience.|
|A.1.A1||Incomplete closure of the embryonic neural tube can cause spina bifida.|
|A.1.A2||Events such as strokes may promote reorganization of brain function.|
|A.1.S1||Annotation of a diagram of embryonic tissues in Xenopus, used as an animal model, during neurulation.|
Nature of science
Use models as representations of the real world - developmental neuroscience uses a variety of animal models. (1.10)
Cultural experiences, including the acquisition of a language, results in neural pruning.