Developmental Cell Changes

Question 1

Mitosis is required for?

Answer 1

Before birth neural stem cells become either neurons or glial cells

Question 2

Migration is?

Answer 2

Neurons move within the developing nervous system to the right location.
-Follow a long glial cell that sends a process to the brain surface and move along it

Question 3

Differentiation is?

Answer 3

Specialization

-Determined by location where the cell migrates to (not predetermined in the cell)

Question 4

What is myelination is?

Answer 4

-Axons of prefrontal cortex of frontal lobe last to myelinated (executive function)

Question 5

Developmental cell changes for spinal nerves at birth are?

Answer 5

• Twice as many neurons as in adult brains in some areas.

- Spinal nerves are well myelinated especially sensory neurons.

Question 6

Developmental cell changes for cranial nerves at birth are?

Answer 6

Cranial nerves are for smell, taste, suck and swallow and are well myelinated

• CNS poorly myelinated
• Brain doubles in size in 1st year in part due to increased myelination

Question 7

What happens at childhood?

Answer 7

Continued myelination of CNS axons

• Synaptogenesis
• Neurons that fail to synapse or are not active enough to die = Pruning
• Critical period/sensitive period for learning
• Time when axons compete for synapses and plasticity is maximized
• Leads to essentinally permanent connections

Question 8

What happens when your teenager?

Answer 8

• Continued myelination = Axons of prefrontal cortex of the frontal lobe (planning, goal setting, reflection)
• Corpus callosum
• Emotional centers
• Higher order language centers
• Synaptogenesis continues = new synapses formed, pruning continues