Brainscape's Knowledge GenomeTM

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


See full index

NEURO-ENDO > Neruo Development > Flashcards

Neruo Development Flashcards

1
Q

What is Neurulatiom?

A

Begins at 16 days

2nd big develop,metal event

Layers and basis of a body plan have begun to form:
Ecto -and Nervous system
Messo- internal organs
Endo- internal linings (gut,linin,etc)

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

Preorganogenesis?

A

2 weeks

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

Embryonic period?

A

3-8 weeks

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

Fetal period?

A

9-38 weeks

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

What effects do external influences on neural development?

Example: alcohol

A

Fetal alcohol syndrome

Craniofacial defects: palate, eyes

Neural defects: IQ, numbers, failure to fold

Brainfolding problems

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

Explain formation of the neural plat

A

Growth without division

Primitive streak (PS) formation (gastrulation) sets up a new axis.

Cells move in from the PS, and anteriorly to form the notochord.

Notochord induces epithelium (ectoderm) to become neural)

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

Describe what happens during Primary Neurulation

A

●Occurs in the Anterior part of the neural tube (NT)
●Only the very end of the tube forms a different way.
●Neural crest cells sit at the edge of the neural plate
●Creation of hinge points:
●Medial: upward
●Dorsolateral: inward
●Closure and delamination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What’s is the mechanism that allows folding of the neural tube?

A

Majority of the neural tube

●Convergent extension to lengthen: not an increase in number

●Formation of hinge points to fold

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

Explain the formation of dorsolateral hinges during primary neurulatuon

A

●BMP involved.
●Noggin (inhibits BMP) → closure. Balance of BMP and noggin allows closure
●BMP involved in shape change: loosens junctional proteins

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

What happens during secondary neurulation ?

A

Posterior neural tube formation:

●Mesenchymal condensation then cavitation
●Evolved in vertebrates with longer tails

●Junctional/transitional zone in between
●Cavitation and migration

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

Explain Neural tube closure and release

A

Zip-like at 4 sites

  1. Extension of lamellipodia and filopodia
    •Interlock and fuse
  2. Release of NT from epiderm (N-cadherin and E-cadherin)
    •Changes in cell adhesion properties
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the consequences of neural tube closure failure?

A

This is the 2nd most common birth defects worldwide

●Spina bifida, anencephaly
●Varies in severity, defects can be significantly reduced with supplementation of Folic Acid. Must be taken early in pregnancy though: start prior to conception

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

What are the different defects due to neural tube closure failure called?

A

Neural tube failure closure in cranial ( brain)

● Anencephaly: cranial (brain)
●Craniorachischisis: brain and spinal cord affected
●Spina Bifida: cervical region down
●Lower back (lumbosacral section) NTDs more common

Anencephaly = absence of brain

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

What does Folate do (importance)?

A

■Role in DNA, RNA, protein and lipid methylation- affects activity and functionality
■DNA repair and replication. It is an enzyme co-factor.
■Also associated with craniofacial defects if not taken

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

What are Neural Crest cells?

A

●Form from the neural epithelium and are carried to sit above the neural tube
●Multipotent stem cells
●Extremely important in forming key structures: craniofacial, pigmentation, adrenal tissue

They create Parasympathetic and sympathetic neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the Role of Neural crest cells?

A

Sit above the neural tube for a short time. Hence neural “crest”
•Migrate to contribute to other tissues and structures
•Position along the tube relates to final outcome

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

What are the origins and derivatives of the Neural crest?

A

Cranial NC: cranial neurons, facial mesenchyme Cardiac NC: tissue wall of large arteries
Trunk NC: dorsal root ganglia- sensory, adrenal medulla, pigment cells
Vagal NC: parasympathetic ganglia

18
Q

Explain the dorso-ventral patterning of the nervous system

A

Roof Plate (no neurons):

Dorsalising: BMP
Commissural neurons ( cross from one side to the other- cell adhesion), 2 sensory neurons, associated interneurons 1 ֯sensory neurons from NC
Floor Plate (no neurons):
Ventralising : SHH
Motor neurons, ventral roots of spinal cord, associated interneurons
19
Q

Explain the anterior posterior patterning of the nervous system

A

Splitting of the brain (encephalisation) into distinct regions (approx. 7 weeks)

Prosencephalon :
Telencephalon
Diencephalon

Mesencaphalon

Rhombencephalon :
Metencephalon
Myelencephalon

Patterns of gene expression set up boundaries that relate to anatomical segmentation.

Otx2: forebrain
Shh: floor plate throughout
Gbx2: hindbrain

20
Q

WHat is encephalisation?

A

Splitting of the brain into regions

21
Q

Explain the external influences that affect the patterning of the nervous system

A

●Patterning also comes from external tissues: node and the mesoderm
●Ie External tissues give a direction, local signals give specific directions

22
Q

What are the steps in neural differentiation?

A

Competence
Specification
Commitment
Differentiation

23
Q

Explain Neural differentiation

A

Neuroepithelia at the lumen of the tube give rise to neuroblasts.

Neuroblasts migrate and differentiate

24
Q

Explain what happens when building a brain: msuktiole layering and multiple cell types

A

●Cells divide, move and differentiate

●Need to create ~170billion plus another ~ 170billion glial cells

25
Q

What happens when building the bar in: inside out?

A

●Neurons migrate outwards.
●First layer of neurons will be the outer layer.
●Subsequent layers formed from inside out. Young over old.
●Each layer will be different
●By 6 months the granular layer of the cerebellum is forming

26
Q

What are the Brain structure: inside out?

A

Ventricular zone:
generative area. Neuroepithelial cells

Mantle zone:
neuroblasts, primitive neural crest cells.
Grey matter. Cell bodies

Marginal zone:
White matter: Myelination of axons from Schwann cells outside spinal cord (Peripheral NS) and Oligodendricytes in spinal cord

27
Q

What are the brain structures formed from inside out differentiation?

A

Neurons will form:
●lamina (layers) or
●clusters (nuclei)

Inner ventricular zone divides and becomes thicker. This is also called the germinal epithelium and will become the brain ependyma (thin layer of cells)

New layer forms (mantle)
Composed of glia and neurons

●Axons head out to create the marginal zone

28
Q

What is Postnatal brain development ? What happens?

A

Avail elaboration : learning and making new experiences- increases number of connections

Synapse elimination

Synapse consolidation

The brain makes many more neural connections than are required in some places. Whether those connections are used is key to their maintenance. Part of brain maturation is growth, but also elimination

29
Q

What is the concepts of Survive or die ?

A

Survival depends on location and species.
Large numbers of neurons die because they do not make synapses
Synapse formation: continues postnatally

30
Q

What happens during maturation of the brain ?

A

Fetal growth rates do not slow for the first 2 years postnatally.

Growth also continues throughout puberty

Brain growth is rapid following birth, relative proportions change until later teenage years.

31
Q

What happens to the brain during puberty?

A

●Not all regions develop at the same time or rate (progress of myelination)
●Frontal lobe: reasoning last to develop
●Pruning of synapses, early teenage years, which affects language acquisition

32
Q

What happens in maturation during puberty?

A

●Emotional pictures shown to young teenagers activates the amygdala (emotional fear and aggression responses)
●Risk taking behaviour increases
●Same picture to older teenagers shows activation of the frontal lobe (reasoned perception)

33
Q

Adult brain more likely to be able to make a reasoned decision, even during emotional stress

True or false?

A

True

34
Q

Can the Brain repair and regenerate?

A

There is some capacity for repair in the brain
●Only 2 regions identified so far:

V-SVZ
●Ventricular –subventricular zone
●Lateral ventricles
●Contributes to olfactory bulb

SGZ-
●Subgranular Zone
●Hippocampus
●glutaminergic granular neurons. Required for memory and cognitive functions.

35
Q

How does repair and regeneration of the Brian take place?

A

●These areas have populations of Neural Stem Cells (NSCs)
●NSCs retain most of the morphology and function of the progenitor cells
●Embryonic Progenitor cells- Radial Glia. Extend from ependymal layer to Blood Vessels
●Low turnover- unlike stem cells in the gut

●B cells: stem cells, Cell types A and C are more differentiated
●In the V-SVZ, the NSCs contribute to the olfactory bulb and striatum
●Activity stimulated by injury, inflammation, exercise, circadian rhythms
●Contact with CSF, blood vessels, electrophysical activity
Seratonin stimulation, paracrine and hormonal factors

36
Q

What is the relationship between the olfactory function and memory?

A

●Decrease in olfactory neurons affects olfactory memory

●Link between odour recognition and olfactory memory and higher order cognitive processin

37
Q

What happens during aging and repair?

A

●Rosettes of B cells surrounded by ependymal cells
●Number of rosettes decreases with aging.
Loss of type B cells with aging: number and size of stem cell niches decreases
●Correlates with a decrease in neurogenic potency
75% decrease in proliferation of NSC and progenitors
●Evidence in SGZ that ability to differentiate decreases.

38
Q

What are stem cells and their subtypes? How are they used for treatment?’

A

ESC: Embryonic Stem Cells
●Pluripotent stem cells
●from primordial germ cells or inner cell mass

EGC: Embryonic Germ Cells
●ESCs in culture

iPSC: induced Pluripotent Stem Cells
●Somatic cell that has activated genes added to enable pluripotency. Will still preferentially differentiate into the original organ cell types

39
Q

What are the questions asked when it comes to using stem cells for treatment?

A 
●Ethical?
●Functional?
        Diseases usually multigenic
        Full integration? Epilepsy
●Immune rejection?
       iPSCs
●Other health risks?
●Disreputable clinics
40
Q

How can stem cells be used as a treatment? And for what?

A

●Human EGCs can cure motor neuron injuries by differentiating into neurons and preventing death of surrounding neurons (Kerr 2003)

●Corneal stem cell transplants
●Spinal repair
●Parkinson’s

41
Q

What are symptoms of Parkinson’s disease?

A 
Symptoms:
•Slowing of movement (akinesia)
•Tremors
•Rigidity
•Flat speech
•Cognitive changes in late stages,
42
Q

How can stem cells treat Parkinson ‘s disease?

A

●Putting dopamine-secreting neurons from EGC into mouse brains can repair Parkinson-like disease in several species
●Use of iPSCs: reduces heterogeneity of ESCs

●Unlikely to cure permanently but may provide respite for 10-15 years. Equivalent to a cure in more elderly patients

NEURO-ENDO (21 decks)

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