Neural development

Question 1

Conceptualization of the Brain

Answer 1

The nervous system is a living organ that grows and changes continuously.
It is influenced by genetic programming and interactions with the environment.

Question 2

Nervous System development

Answer 2

Begins early in embryonic development and continues throughout life.

Question 3

multiplication

Answer 3

Refers to the rapid increase in the number of neural precursor cells.

Question 4

Initial development

Answer 4

• Begins shortly after fertilization with the development of the neural tube, which differentiates into the brain and spinal cord.
• The neural tube undergoes further specialization and segmentation.

Question 5

Development of Neurons

Answer 5

Neurons are generated from neural stem cells through neurogenesis.
includes
- Proliferation
- Migration
- aggregation
- axon growth

Question 6

Proliferation

Answer 6

The rapid multiplication of neural precursor cells.
Occurs during early nervous system development.
Generates a pool of precursor cells that differentiate into neurons and glial cells.

Question 7

migration

Answer 7

Neurons move to their appropriate locations within the developing nervous system.

Question 8

Aggregation

Answer 8

The clustering of neurons into distinct structures.
Mediated by Neural Cell Adhesion Molecules (NCAMs).
Crucial for the formation of functional neural circuits.

Question 9

Axon growth

Answer 9

Neurons differentiate, forming axons and dendrites.
Myelination occurs gradually, speeding up neural impulses.
Synaptogenesis involves forming synapses between neurons.
Axons find their target connections through chemoaffinity.

Question 10

Induction

Answer 10

Occurs during early embryonic development.
Involves the formation of the neural tube through neurulation.
Mediated by signaling molecules like BMP and Noggin.
The neural tube undergoes morphogenetic movements to become the precursor to the central nervous system.

Question 11

Neuroplasticity

Answer 11

The brain’s ability to reorganize itself in response to experience.
Involves synaptic rearrangement and neural reorganization.
Developmental plasticity occurs from normal development to adulthood.
Adaptive plasticity compensates for lost function or maximizes remaining functions.

Question 12

animal evidence of neuroplasticity

Answer 12

Studies injecting dye to visualize neurons.
Showed approximately 6% change in dendritic structure over a month.
Dendritic trees of two neurons from a single mouse showed both extension and retraction

Question 13

Hubel et al. (1977)

Answer 13

YES development is limited to the early development period
- monocular deprivation influence the development of ocular dominance columns in the visual cortex only if in the first few weeks of life

Question 14

Recanzone et al. (1992)

Answer 14

Development is not limited to the period of early development
* third digit stimulation in older primates&raquo_space; increased representation in somatosensory cortex
- It is now recognised that the mammalian brain retains the ability to undergo substantial reorganisation

Question 15

Human Neuroplasticity

Answer 15

• different types of plasticity: developmental and adaptive
• synaptic rearrangement: occurs across the lifespan, aiming for efficiency
• Neural reorganisation: rapid changes from experiences and gradual change from neural damage

Question 15

Synaptic Rearrangement

Answer 15

Occurs across the lifespan, focusing output of neurons on fewer postsynaptic neurons.
Involves strengthening existing connections and establishing new ones.
Underpins developmental and adaptive plasticity.

Question 16

Neural Reorganization

Answer 16

Rapid change involves strengthening existing connections from experiences.
Gradual change involves establishing new connections from neural damage.
Includes processes like collateral sprouting.

Question 17

Chemoaffinity

Answer 17

Primary driver of how growth cones reach their destination during axon growth.
Involves each postsynaptic surface releasing specific chemicals to attract or repel particular growing axons.
Distortions in chemical distribution during early development can lead to significant impairments.

Question 18

Synaptogenesis

Answer 18

Final stage of neural development involving the formation of synapses between neurons.
Axons initially form synapses with several cells, which are then strengthened or eliminated based on activity.
Continues throughout life, albeit at a slower rate later in life.

Question 19

Myelination

Answer 19

Process by which glia produce the fatty sheath covering axons of some neurons.
Speeds up transmission of neural impulses.
Initially occurs in the spinal cord and progresses to the hindbrain, midbrain, and forebrain.

Question 20

Governing principles of neural development

Answer 20

• these are very similar to the principals governing our psychosocial development
  
  1. Identity:
     
     • some become muscle cells, multipolar neurons, glial cells, etc.
  2. Travel:
     
     • make way to appropriate sites and join to form structures
  3. Relations/Connectivity:
     
     • establish appropriate functional relations