Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MD1 Neuroscience > Development of the Nervous System > Flashcards

Development of the Nervous System Flashcards

1
Q

What are the main steps in the development of the nervous system?

A 
Neural induction
Neurulation
Morphogenesis and patterning of neural tube
Neurogenesis
Neuronal migration
Axon growth and pathfinding, and dendritic arborisation
Synaptogenesis
Gliogenesis/myelination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define neural induction

A

Assigning neural potential to region of early embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define neurulation

A

Forming rudimentary nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define neurogenesis

A

Production of neurons and glia from precursor cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define neuronal migration

A

Neurons move from sites of production to positions in mature brain
Makes space for new neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define synaptogenesis

A

Making and refining synaptic connections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In what stages of nervous system development does apoptosis occur?

A 
Neurogenesis
Neuronal migration
Axon growth and pathfinding, and dendritic arborisation
Synaptogenesis
Gliogenesis/myelination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which part of the embryo acquires a neural fate?

A

Region of dorsal embryonic ectoderm = neural plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What forms from the neural plate?

A

Entire CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens to the rest of the ectoderm?

A

Acquires epidermal fate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What determines epidermal fate?

A

Local bone morphogenetic protein (BMP) signalling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the organiser region of the neural plate, and what does it do?

A

Intermediate marginal zone

Cells underneath programmed to secrete inhibitors that stop cells above from becoming epidermis - block BMP signal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a neurula?

A

An embryo that has undergone neural induction

Happens at 3 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is neurulation?

A

Formation of the neural tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is the neural tube formed?

A 
Neural plate cells become more columnar
Elevation of neural folds
Neural folds fuse in dorsal midline
Neural tube pinches off from epidermis
Occurs all the way along the embryo
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the inside of the neural tube, and what does it contain?

A

Ventricle

Contains fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

In which direction does the neural tube zip up?

A

Bidirectionally from initial point of closure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where are the two points of closure of the neural tube?

A

Hindbrain-cervical boundary

Forebrain-midbrain boundary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What causes neural tube defects?

A

Failure of neural fold formation or closure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What doesn’t close in spina bifida?

A

Caudal neuropore

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What doesn’t close in anencephaly?

A

Cranial neuropore

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the role of folate thought to be?

A

Enhancing cellular competency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where do neural crest cells develop?

A

At neural plate margin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

When do neural crest cells migrate?

A

When dorsal margins of tube fuse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Where do neural crest cells migrate?

A

From dorsal to ventral side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What do neural crest cells give rise to?

A 
Dorsal root ganglia
Sympathetic ganglia
Adrenal medulla
Enteric NS ganglia
Melanocytes
Schwann cells
Cartilage and bone of face and jaw
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What happens after the neural tube closes?

A

Primary and secondary brain vesicles form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Describe the primary and secondary brain vesicles

A

Wall = neuroepithelium

Fluid-filled central cavity = ventricular system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the three vesicles that form at the rostral end of the neural tube?

A 
Prosencephalon = forebrain
Mesencephalon = midbrain
Rhombencephalon = hindbrain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does the prosencephalon split into?

A

Telencephalon

Diencephalon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What does the rhombencephalon split into?

A

Metencephalon

Myelencephalon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What does the telencephalon give rise to?

A

Olfactory bulb
Cerebral cortex
Hippocampus
Striatum/basal ganglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What does the optic vesicle give rise to?

A

Retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What does the diencephalon give rise to?

A

Thalamus

Hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What does the mesencephalon give rise to?

A

Midbrain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What does the metencephalon give rise to?

A

Pons

Cerebellum

37
Q

What does the myelencephalon give rise to?

A

Medulla

38
Q

What provides the different positional cues for specifying cell fate?

A

Gradients of morphogens from patterning centres or organising regions

39
Q

What induces the roof plate?

A

Overlying ectoderm

40
Q

What does the roof plate secrete?

A

Dorsalising morphogens

41
Q

What induces the floor plate?

A

Underlying notochord

42
Q

What does the floor plate secrete?

A

Ventralising morphogen

43
Q

What cell types are derived because of the roof plate?

A

Interneurons

Oligodendrocytes

44
Q

What cell types are derived because of the floor plate?

A

Motor neurons

45
Q

How many layers does the neuroepithelial lining of the brain vesicles have?

A

1

46
Q

Why do the neuroepithelial cells in the vesicles appear multi-layered?

A

Nucleus develops at ventral end
Cell extends processes dorsally
Nucleus moves up and down processes with different phases of cell cycle
Called interkinetic nuclear migration

47
Q

Where are neuroepithelial cells and what do they give rise to?

A

In ventricular zone
Self-replicate
Give rise to radial glia

48
Q

Where are radial glia and what do they give rise to?

A

In ventricular zone

Self-replicate, and give rise to intermediate progenitors and astrocytes = asymmetrical cell divisions

49
Q

Where are the intermediate progenitors and what do they give rise to

A

In sub-ventricular zone

Give rise to neurons

50
Q

What are radial glial cells?

A

Neural stem cells

51
Q

What are symmetric divisions?

A

Produce two identical daughter cells
Expand neuroepithelial progenitor pool early
Give rise to two neurons late

52
Q

What are asymmetric divisions?

A

Produce two different daughter cells

Radial glia divide and produce a radial glial cell and a differentiated neuron

53
Q

What is the structural role of radial glia?

A

Provide scaffold for radial migration of neuron progeny

54
Q

Where do the neuronal progeny of radial glia migrate to?

A

Away from ventricular zone towards pial surface of brain

55
Q

What is the order of cortical layer formation?

A

Earliest form preplate
Preplate splits into marginal zone and subplate when first wave of cortical plate neurons arrive
Neurons of cortical plate assemble into layers II-VI in inside-out way
- Deepest layers first

56
Q

Where are the stem cells of the adult brain?

A

At ventricle

57
Q

What do stem cells of the adult brain produce?

A

Neurons for olfactory bulb

58
Q

Where are cortical interneurons produced?

A

Basal forebrain

59
Q

Along what do olfactory bulb neuroblasts migrate?

A

Rostral migratory stream

60
Q

Where do cerebellar granule cell precursors originate>

A

Rhombic lip

61
Q

What are some neuronal migration disorders?

A 
Schizencephaly = clefts in brain
Lissencephaly = smooth brain
Agyria = lack of folds
pachygyria = thick folds
Polymicrogyria/microgyria = many/small folds
Neuronal heterotopia = other place, including band heterotopia = double cortex
Agenesis of corpus callosum
Agenesis of cranial nerves
62
Q

What are some symptoms of neuronal migration disorders?

A

Vary
Poor muscle tone and motor function
Seizures
Developmental delay and impaired cognitive development
Failure to grow and thrive, and difficulties with feeding
Smaller than normal head

63
Q

How is grey matter heterotopia formed?

A

Neurons fail to migrate from ventricle, or migrate halfway to cortical plate

64
Q

What is the result of grey matter heterotopia?

A

Disorganised patches or bands of misplaced neurons

65
Q

What is band heterotopia caused by?

A

DCX mutation on X chromosome

66
Q

What happens in band heterotopia?

A

Neurons that fail to migrate accumulate below layer of white matter

67
Q

How does a cobblestone cortex occur?

A

Neurons overshoot cortical plate and reside in layer I

68
Q

Are neurogenesis and gliogenesis controlled by the same transcriptional programs?

A

No

They also inhibit each other

69
Q

What occurs first: neurogenesis or gliogenesis?

A

Neurogenesis

70
Q

What proportion of neurons are pyramidal?

A

80%

71
Q

What do pyramidal neurons do?

A

Excitatory long-range projection neurons

Axons project to other cortical hemisphere or sub-cortical targets like spinal cord

72
Q

What proportion of neurons are interneurons?

A

20%

73
Q

What do interneurons do?

A

Mainly locally-projecting inhibitory neurons

Modulate cortical excitatory output

74
Q

How does the dendritic arbor develop?

A 
Basic plan genetically specified
Growth and branching influenced by environmental factors
- Local signals
   - Contact-dependent
   - Diffusible cues
- Active synapses
75
Q

How do dendrites and axons grow?

A

Repulsion of outgrowing axon
Attraction of apical dendrite
Elongation/retraction and branching of apical/basal dendrites
Activity-dependent spine stabilisation

76
Q

What controls the extent of the dendritic arbor?

A

Growth factors

77
Q

Where does axon growth happen?

A

At the very motile tip of the neurite = growth cone

78
Q

What do actin filaments do in growth cones?

A

Regulate shape and directed growth of growth cone

79
Q

Where are these actin filaments in the growth cone?

A

Filopodia

80
Q

What do microtubules do in the growth cone?

A

Provide structural support to axon shaft
Essential for axon extension
Help push growth cone forward

81
Q

When do microtubules grow in?

A

After actin filaments stabilise

82
Q

What sort of environmental guidance cues steer growth cones?

A

Gradient of long-range repellent and attraction
Contact adhesion and repulsion
Growth cone senses and integrates signals

83
Q

What is the corpus callosum?

A

Largest fibre tract in brain

Formed by axons projecting to opposite hemisphere

84
Q

What do axon guidance defects result in?

A

Complete or partial failure of corpus callosum to form

85
Q

What are the symptoms of agenesis of the corpus callosum?

A 
Variable severity
Sensory and motor deficits including:
- Vision impairments
- Low muscle tone
- Poor muscle coordination
- Delays in motor milestones
Cognitive disabilities; eg in:
- Complex problem solving
- Missing subtle social cues
86
Q

When do gyri and sulci start to develop?

A

Seven months of gestation

87
Q

What processes in brain development continue or happen after birth?

A

Axonal and dendritic outgrowth
Synapse formation
Myelination

88
Q

What is the relative rate of development of excitatory and inhibitory synapses?

A

Excitatory synapses peak a lot earlier than inhibitory synapses develop

89
Q

What does refinement of of synapses involve?

A

Connections originally overproduced
Performance improved by adjusting number, boundaries, and strength of connections through competitive process
Eg: poly- to mono-innervation at developing neuromuscular junction

MD1 Neuroscience (55 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions