2.2 Development of nervous system

Question 1

What are the 6 cortices and lobes of the brain?

Answer 1

1. motor (movement)
2. somatosensory (receives sensory input)
3. occipital lobe (vision)
4. temporal lobe
5. auditory cortex
6. parietal lobe

Question 2

What is neural induction?

Answer 2

assigning of neural potential to region of embryoW

Question 3

What is neurulation?

Answer 3

formation of rudimentary nervous system

Question 4

What is morphogenesis?

Answer 4

patterning of the neural tube

Question 5

What is neurogenesis?

Answer 5

production of neurons and glia from precursor cells

Question 6

What is neural migration?

Answer 6

neurons move from sites of production to their positions in the mature brain

Question 7

What is axon growth and pathfinding?

Answer 7

neurons find appropriate targets for dendritic arborisation to occur

Question 8

What is synaptogenesis?

Answer 8

refines and makes synaptic connections, followed by myelination

Question 9

What are the steps of construction of NS?

Answer 9

1. neural induction
2. neurulation
3. morphogenesis
4. neurogenesis
5. neural migration
6. axon growth
7. synaptogenesis

Question 10

What layer of acquires neural fate?

Answer 10

dorsal ectoderm

Question 11

What part of embryo is CNS formed from?

Answer 11

neural plate

Question 12

How is epidermal fate decided?

Answer 12

through BMP gene. signals from organiser regions block BMP signals inducing neural fate

Question 13

Where does gastrulation occur?

Answer 13

uterine wall after implantation

Question 14

What occurs during neurulation?

Answer 14

neural plate folds fusing in the dorsal midline to form neural tube

Question 15

What causes spina bifida/

Answer 15

neural tube does not close, neural tube zips up bi-directionally from initial points of closure

Question 16

Where do neural crest cells originate?

Answer 16

cells at end of neural plate

Question 17

What do neural crest cells give rise to?

Answer 17

peripheral and enteric NS ganglia

Question 18

What causes the primary and secondary vesicles to form?

Answer 18

morphogenesis and patterning of neural tube after neural tube closes

Question 19

What are the 3 main vesicles that form at cranial end of neural tube?

Answer 19

1. prosencephalon (forebrain)
2. mesencephalon (midbrain)
3. rhombencephalon (hindbrain)

Question 20

What are the 5 vesicles in the 5 vesicle stage?

Answer 20

1. telencephalon
2. diencephalon
3. mesencephalon
4. metencephalon
5. myelencephalon

Question 21

What doe the telencephalon become?

Answer 21

olfactory bulb, cerebral cortex hippocampus, striatum/basal ganglia

Question 22

What does the diencephalon become?

Answer 22

thalamus and hypothalamus

Question 23

What does the mesencephalon become?

Answer 23

midbrain

Question 24

What does the metencephalon become?

Answer 24

pons and cerebellum

Question 25

What does myelencephalon become?

Answer 25

medulla

Question 26

What are three examples of moralising morphogens?

Answer 26

BMPS, FGF, Wnts

Question 27

What does the notochord develop from?

Answer 27

mesoderm

Question 28

How does dorsal and ventral regions of the brain form?

Answer 28

competing dorsalising and centralising morphogens in the neural tube

Question 29

What determines if an area becomes an interneuron or a motor neuron?

Answer 29

closer to roof plate = interneuron
closer to floor plate = motor neuron

Question 30

Which is the apical and basal side of the neuroepithelium?

Answer 30

apical - close to ventricles
basal - close to where spinal cord will develop

Question 31

What is special about neuroepithelial cells and radial glia (hint: progenitor)

Answer 31

both are multipoint neural progenitor cells

Question 32

Where are neural progenitor cells produced and where do they migrate?

Answer 32

produced in ventricular zone, as they develop, move towards basal surface

Question 33

What do radial glia become?

Answer 33

astrocytes

Question 34

What do symmetric divisions result in?

Answer 34

expansion of neuroepithelial layer or two identical daughter cells (neurons)

Question 35

What do asymmetric divisions result in?

Answer 35

radial glia which divide and produce more radial glia and a differentiated neuron, so produce two different daughter cells

Question 36

How do excitatory neurons grow?

Answer 36

inside out sequence
grow in dorsal and move towards surface of brain

Question 37

How do inhibitory neurons grow?

Answer 37

come from MGE so produced in diff regions

Question 38

Which comes first - neurogenesis or gliogenesis

Answer 38

Neurogenesis. They block each others actions.

Question 39

Where does the information flow in neurons start and end?

Answer 39

Starts at dendrites, collecting electrical signals. Sends to cell body, generating outgoing signals to axon. Axon passes electrical signals to dendrites of other cel.

Question 40

What is seen on the end of a growing axon?

Answer 40

Growth cone

Question 41

What are pyramidal neurons?

Answer 41

Excitatory long range projection neurons. Axons project to other cortical hemisphere or spinal cord

Question 42

What are interneurons?

Answer 42

Locally projecting inhibitory neurons which modulate cortical excitatory output

Question 43

How many layers in the cortex?

Answer 43

6

Question 44

What happens in dendrite and axon growth?

Answer 44

Repulsion of outgrowing axon caused by Sema3A and Slit1, attraction of main apical dendrite , elongation/retraction and branching of apical/basal dendrites

Question 45

What do actin filaments do?

Answer 45

Regulate shape and directed growth of growth cone

Question 46

What do microtubules do?

Answer 46

Provide structure

Question 47

What do filopodia do?

Answer 47

Receive signals from environment to determine where to go