Ch. 5: Development of Neuroscience

Question 1

Fetal

Answer 1

• 8th week to birth
• Brain formation continues
• Myelination begins

Question 2

Pre-Embryonic

Answer 2

• conception to 2nd week

- Before organs formed

Question 3

Embryonic

Answer 3

-2nd week to 8th week

Question 4

Neural Plate

Answer 4

• Root of all nerve cells

- all nerve cells grow from neural plate

Question 5

Neural tube

Answer 5

-crests of neural groove grow and connect to form tube

Question 6

Neural Crest

Answer 6

• part of neural plate that got pinched off when neural tube formed
• differentiates into all somatosensory neurons in body

Question 7

Neural Groove

Answer 7

-Valley in middle of neural plate

Question 8

Neuropores

Answer 8

• superior and inferior

- openings at top and bottom of neural tube

Question 9

Mantle Layer

Answer 9

• inner ring of cell bodies in neural tube

- grey matter

Question 10

Marginal Layer

Answer 10

• outer ring of axons/glia in neural tube

- white matter

Question 11

Motor Plate

Answer 11

• (basal, ventral)
• contains motor neurons–ventral horn
• front of mantle layer will connect to myotome

Question 12

Neural Crest Diversification

Answer 12

• Peripheral sensory neurons
• myelin cells
• autonomic neurons
• endocrine organs

Question 13

Initial Brain Formation

Answer 13

• Hind brain (medulla, pons, cerebellum)
• Midbrain
• Forebrain (cortical and subcortical structures)

Question 14

Association Plate

Answer 14

• (alar, dorsal)
• contains interneurons and sensory neurons (dorsal horn)
• dorsal mantle layer (will connect to dermatome)

Question 15

2 Phases of Nervous System Development

Answer 15

1. neural tube formation

2. initial brain formation

Question 16

Mantle Divisions

Answer 16

• Motor plate (myotome)

- Association Plate (dermatome)

Question 17

Somite

Answer 17

• develops from mesoderm
• cells on either side of neural tube
• 3 Parts (sclerotome, myotome, dermatome)

Question 18

Sclerotome

Answer 18

• becomes skull and vertebrae

- anteromedial part of somite

Question 19

Myotome

Answer 19

• becomes skeletal muscles

- posteromedial part of somite

Question 20

Dermatome

Answer 20

• becomes dermis

- Lateral part of somite

Question 21

Migration of Mantle Layer

Answer 21

-Grey matter from inner layer ziplines to outer layer of brain

Question 22

Neurons Differentiate After:

Answer 22

-migrating to their final location

Question 23

Growth Cone

Answer 23

-growing axon out toward target

Question 24

Neural Remodeling

Answer 24

• at first we have way more neurons and connections than we need
• activity shapes connections (increase or decrease strength)

Question 25

Axon retraction

Answer 25

- the axon loses competition for permanent connection - pulls axon back (may go elsewhere or dies) - Synaptic pruning

Question 26

Fast Motor Neuron

Answer 26

- Goes to fast twitch muscle - large axon diameter - highly myelinated

Question 27

Neuron Connections

Answer 27

1. Growth Cone 2. NT Release 3. Synaptic Connections Formed

Question 28

Synaptic Connections Formed

Answer 28

-Axons differentiate based on connections they make

Question 29

Neuronal death

Answer 29

-doesn't make valid connections and neuron dies

Question 30

Myelination

Answer 30

- Begin at 4th fetal month | - end around 3 years

Question 31

Slow Motor Neuron

Answer 31

- goes to slow twitch muscle - small axon diameter - less myelination

Question 32

Anencephaly

Answer 32

- neural tube doesn't close at top - only rudimentary brain stem; no cerebellar hemispheres - skull doesn't form over incomplete brain

Question 33

Neural Tube Defects

Answer 33

- Anencephaly - Arnold-Chiari Malformation - Spina Bifida

Question 34

Arnold-Chiari Malformation

Answer 34

- neural tube and foramen magnum get out of alignment | - neural tube slides down and part of cerebellum, medulla and pons are out of foramen magnum and squished against bone.

Question 35

Cerebral Palsy

Answer 35

- permanent, non-progressive damage to brain before, during or after birth - movement/posture disorders, cognitive, somatosensory, visual, auditory, speech deficits - deficits depend when damage occur - "growing into" deficits common

Question 36

Spina Bifida

Answer 36

- failure of neural tube to close at bottom | - vertebrae don't fully or close around the incomplete spinal cord

Question 37

"Growing Into"

Answer 37

- different rates in different areas of myelination - peripheral motor (~1 month) - Central motor (~2 years) - May not know a disorder is there until kid is older