Lesson 6: Post Embryonic Neural Development

Question 1

embryonic development

Answer 1

During embryonic development, regulated gene expression and signal transduction establish the overall structure of the nervous system.

Two processes work on further development and remodelling:

Competition among neurons

Synapse elimination

Question 2

Competition among Neurons

Answer 2

Neurons compete for growth-supporting factors developed in tissues to direct neuron growth.

Neurons that do not reach their proper location do not receive these factors and undergo apoptosis (programmed cell death).

Half of all embryonic neurons are eliminated this way. This is known as neural pruning.

This process ensures the preferential survival of properly located neurons.

Question 3

Synapse Elimination

Answer 3

The developing neuron forms more synapses than are necessary for proper function.

Synapses that are used leave chemical markers in the synapse after transmission that strengthens the synapse.

Synapses that are not used do not contain these markers and become weaker until they are eliminated.

Question 4

Neural Plasticity

Answer 4

Neural plasticity is the capacity of the nervous system to be remodeled in
response to its own activity is known as neural plasticity.

The degree of plasticity is higher in young children (up to age six) than adolescents and adults.

The nervous system can establish new synapses through the growth of
dendrites and axons. It can also eliminate synapses by pruning dendrites, axons and whole cells.

This plasticity allows for forming new memories, learning and advanced
reasoning.