Early Development Lec02 Flashcards Preview

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Flashcards in Early Development Lec02 Deck (73):
1

Gastrulation defines the ___, ___, and ___ axes of the nembryo

midline, anterior-posterior and dorsal-ventral

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2

the midline of the embryo is defined by the formation of the ____

notocord

3

notocord is formation incudes the formation of the ____

neural ectoderm

4

____ formationn is the ver y first event in neurogenesis

otochord formation

5

___ are the neural rpecurosr cells, which turns into CNS

neural ectoderm

6

if you treat ectoderm with ___ you get epidermis

bmp (a transforming growth factor beta)

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7

if you treat ectoderm with ___ you get NEUROECTODERM

noggin chordin (inhibit BMP)

8

BMPs are made by the ____

surrounding tissue

9

Factors that inhibit BMP signaling are produced by the ____ (

notochord

10

___ signaling precedes BMP inhibition during neural induction

FGF

11

what do noggin and chordin do?

block bmp (thus, inducing neural development)

12

FGF stimulation increases production of ____

Noggin

13

neural induction the lateral margins of the____ fold inward to form the \n\nneural tube

neural plate

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14

neural tube forms around day ___

20

15

the____ pinches off when the NEURAL TUBE is formed

neural crest

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16

Neural tube closes from the middle both____ and ___

anteriorly and posteriorly (like a zipper going in both directions)

17

____ vitamins in the first few weeks of \n\npregnancy decrease neural tube closure defects.

B-complex (folic acid)

18

Spina Bifida rate in US is much lower since ____

nutrition

19

Spina Bifida is the failure of the ____ end of the neural tube to close

posterior

20

Anencephaly and holoprosenchephaly (Represents failure of the ___ neural tube to close.

anterior

21

Anencephaly and holoprosenchephaly lack ___

forebrain

22

____ makes cells in one area different from cells in another area

patterning

23

ventral patterning is realted to ___ function

motor

24

ventral siganl is secreted ____

sonic hedgehog

25

dorsal siganl is secreted ____

tgf betas

26

sonic hedgehog eventually leads to differences in ____

trnascription

27

What produces dorsal ventral polarity?

high sonic hedgehog in notocord and roof plate

no sonic headhog in the roof plate

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28

roteins encoded by hox genes are powerful ____

transcriptional activators and repressors

29

results from abscence of sonic hedgehog:

1. The forebrain does not form

2. dorsal ventral polarity is disrupted

30

y dirsruptions in ____ also can cause cancers such as \n\nmedulloblastomas and basal cell carcinoma.

sonic hedgehog

31

Shh not only regulates polarity but ___

proliferation (disruptions in shh pathway can lead to different cancers)

32

cyclopy can be caused by abseence of ___

sonic hedge hog

33

when does anterior/posterior patterning occur? (relatively)

same time as neural induction and gastrulation (they all overlap)

34

spinal cord is from ___ patterning

anterior/posterior

35

rhomboencephalon is the future ___ and ___

pons and medulla

36

mesencephalon is the future ___

midbrain

37

diecepahlona nd telcephalon are part of the ____

prosencephalon

38

difference between fly and human hox genes\n

in humans they identify a specific segment along the anterior/posterior axis

39

Hox genes are involved in defining segmental differences in the ___, ___, and ___

spinal cord, \n\nmedulla and pons.

40

anterior/posterior patterning is accomplished through ___ genes

hox

41

there is no hox code for the ___ and ___

prosecenphalon and mesencephalon

42

OTX2 knockouts show complete loss of ____ polarity.

anterior

43

coordination of ___ and ___  regulates nervous system expansion

symmetrical and asymthetical proliferation

44

____ is needed to organize distinct cell types into functional units

cell migration

45

___ and ____s divide and differentiate in the ventricular zone

Neural stems cells and neural progenitor cell

46

multipotent stem cell either ___ or ___

neuronal or glial precurosr cells

47

___ increases the size of the ventricular zone, which in turn increases the size nof the brain.

symmetrical divisons

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48

pluripotrnt neural stem cells are capable of ____

self renewal

49

As development proceeds NSCs begin to divide asymmetrically giving rise to 

one neural stem cell and one neuro precursor

50

Late in development NSCs will again divide symmetrically but give rise to two

neural pecursors (and therefore NSC disappear) 

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51

number of NSCs, progenitors, neurons and glia needs to be tightly controlled as \n\ndoes the timing of their generatio by ___ and ___

notch and bhlh transcription factor

52

notch ____ proneural gene

deactivates

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53

if you remove the inhibition of proneural gene by notch in the neural stem cell ____ is upregulated

delta

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54

what happens at low/moderate levels of Notch stimulation through Delta? 

, the intracellular domain of Notch is cleaved and goes to the nucleus to activate bHLH genes. (cell is eventually primed to diff into a neuron)

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55

bHLH activation also ___ Delta on neural stem cells cells.

upregulates

56

Notch gets hyper-activated (by delta after it is upregulated)--> 

 shuts off proneuronal bHLH genes ----> keeping cell in pluripotent nsc state

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57

In this case astrogliogenesis differentiation from neural progenitors is ___ \n\ndependent

Notch

58

astrogliogenesis differentiation from neural progenitors is inhbiited by ___

bhlh genes

59

oligodendrocyte generation is induce

by other factors (Oligs and Nkx 2.1) (factor other than nox)

60

neurogenesis is finished by the \n\nmiddle of the ____ trimester.

second

61

Timing of gliogensis happens mostly

after birth

62

The basic shape of the brain is fully formed at birth and the vast majority of the \n\n____ are already generated.

neurons

63

difference in brain after birth

dramatic increase in brain size, inc in myelin

64

primary neurlaiton is complete within the ___ weeks

first 3

65

most neurons in the cerebral cortex are produced between the ___ and ___ month of pregancy

first and 4th

66

f ectodermal pecursor cells are isolated and grown in a dish, they become ____

neurons (since there is no BMP present)

67

Stimulation of____ factors induce neural stem cell formation.

 retinoic acid (RA), fibroblast growth factor (FGF) and insulin-like growth factor (IGF

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68

what process are hox genes involved in?

posterior processing

69

how do hox genes create unique patterns of gene expression? 

through repressing and enhancing each other 

70

___ promotes astrogliogensis

notch

71

___ promotes oligodenrodensis

Olig1/2, Nkx 2.1 

72

___ inhibits Oligodendrogenesis

BHLH

73

___ inhbiits Astrogliogenesis:

BHLH