Early Development Lec02 Flashcards Preview

Neuroscience > Early Development Lec02 > Flashcards

Flashcards in Early Development Lec02 Deck (73)
Loading flashcards...
1
Q

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

A

midline, anterior-posterior and dorsal-ventral

2
Q

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

A

notocord

3
Q

notocord is formation incudes the formation of the ____

A

neural ectoderm

4
Q

____ formationn is the ver y first event in neurogenesis

A

otochord formation

5
Q

___ are the neural rpecurosr cells, which turns into CNS

A

neural ectoderm

6
Q

if you treat ectoderm with ___ you get epidermis

A

bmp (a transforming growth factor beta)

7
Q

if you treat ectoderm with ___ you get NEUROECTODERM

A

noggin chordin (inhibit BMP)

8
Q

BMPs are made by the ____

A

surrounding tissue

9
Q

Factors that inhibit BMP signaling are produced by the ____ (

A

notochord

10
Q

___ signaling precedes BMP inhibition during neural induction

A

FGF

11
Q

what do noggin and chordin do?

A

block bmp (thus, inducing neural development)

12
Q

FGF stimulation increases production of ____

A

Noggin

13
Q

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

A

neural plate

14
Q

neural tube forms around day ___

A

20

15
Q

the____ pinches off when the NEURAL TUBE is formed

A

neural crest

16
Q

Neural tube closes from the middle both____ and ___

A

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

17
Q

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

A

B-complex (folic acid)

18
Q

Spina Bifida rate in US is much lower since ____

A

nutrition

19
Q

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

A

posterior

20
Q

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

A

anterior

21
Q

Anencephaly and holoprosenchephaly lack ___

A

forebrain

22
Q

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

A

patterning

23
Q

ventral patterning is realted to ___ function

A

motor

24
Q

ventral siganl is secreted ____

A

sonic hedgehog

25
Q

dorsal siganl is secreted ____

A

tgf betas

26
Q

sonic hedgehog eventually leads to differences in ____

A

trnascription

27
Q

What produces dorsal ventral polarity?

A

high sonic hedgehog in notocord and roof plate

no sonic headhog in the roof plate

28
Q

roteins encoded by hox genes are powerful ____

A

transcriptional activators and repressors

29
Q

results from abscence of sonic hedgehog:

A

1. The forebrain does not form

2. dorsal ventral polarity is disrupted

30
Q

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

A

sonic hedgehog

31
Q

Shh not only regulates polarity but ___

A

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

32
Q

cyclopy can be caused by abseence of ___

A

sonic hedge hog

33
Q

when does anterior/posterior patterning occur? (relatively)

A

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

34
Q

spinal cord is from ___ patterning

A

anterior/posterior

35
Q

rhomboencephalon is the future ___ and ___

A

pons and medulla

36
Q

mesencephalon is the future ___

A

midbrain

37
Q

diecepahlona nd telcephalon are part of the ____

A

prosencephalon

38
Q

difference between fly and human hox genes\n

A

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

39
Q

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

A

spinal cord, \n\nmedulla and pons.

40
Q

anterior/posterior patterning is accomplished through ___ genes

A

hox

41
Q

there is no hox code for the ___ and ___

A

prosecenphalon and mesencephalon

42
Q

OTX2 knockouts show complete loss of ____ polarity.

A

anterior

43
Q

coordination of ___ and ___  regulates nervous system expansion

A

symmetrical and asymthetical proliferation

44
Q

____ is needed to organize distinct cell types into functional units

A

cell migration

45
Q

___ and ____s divide and differentiate in the ventricular zone

A

Neural stems cells and neural progenitor cell

46
Q

multipotent stem cell either ___ or ___

A

neuronal or glial precurosr cells

47
Q

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

A

symmetrical divisons

48
Q

pluripotrnt neural stem cells are capable of ____

A

self renewal

49
Q

As development proceeds NSCs begin to divide asymmetrically giving rise to 

A

one neural stem cell and one neuro precursor

50
Q

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

A

neural pecursors (and therefore NSC disappear) 

51
Q

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

A

notch and bhlh transcription factor

52
Q

notch ____ proneural gene

A

deactivates

53
Q

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

A

delta

54
Q

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

A

, 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)

55
Q

bHLH activation also ___ Delta on neural stem cells cells.

A

upregulates

56
Q

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

A

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

57
Q

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

A

Notch

58
Q

astrogliogenesis differentiation from neural progenitors is inhbiited by ___

A

bhlh genes

59
Q

oligodendrocyte generation is induce

A

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

60
Q

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

A

second

61
Q

Timing of gliogensis happens mostly

A

after birth

62
Q

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

A

neurons

63
Q

difference in brain after birth

A

dramatic increase in brain size, inc in myelin

64
Q

primary neurlaiton is complete within the ___ weeks

A

first 3

65
Q

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

A

first and 4th

66
Q

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

A

neurons (since there is no BMP present)

67
Q

Stimulation of____ factors induce neural stem cell formation.

A

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

68
Q

what process are hox genes involved in?

A

posterior processing

69
Q

how do hox genes create unique patterns of gene expression? 

A

through repressing and enhancing each other 

70
Q

___ promotes astrogliogensis

A

notch

71
Q

___ promotes oligodenrodensis

A

Olig1/2, Nkx 2.1 

72
Q

___ inhibits Oligodendrogenesis

A

BHLH

73
Q

___ inhbiits Astrogliogenesis:

A

BHLH