Neuro 101B Test 1

Front 1

Endoderm becomes

Back 1

gut, lungs bladder etc

Front 2

Mesoderm becomes

Back 2

skeleton, muscles, heart and notocord

Front 3

Ectoderm becomes

Back 3

nervous system and skin

Front 4

What is Gastrulation

Back 4

Changing from a blastula to a gastula

Front 5

The involuting marginal zone IMZ is destined to become

Back 5

Mesoderm

Front 6

What happens if you transplant a second dorsal lip into an embryo?

Back 6

A secondary neural tube will develop

Front 7

The derivatives of the notocord include (3)

Back 7

mesoderm, Spemann's organizer, dorsal blastopore lip

Front 8

What gene was isolated as cDNA and found to rescue UV treated embryos by inducing neural tissues?

Back 8

Noggin

Front 9

Chordin is a gene expressed where?

Back 9

Dorsal blastopore lip.

Front 10

What receptor does BMP bind to?

Back 10

TGF beta receptor

Front 11

What results if BMP binds to a mutated receptor that cannot signal intracellularly?

Back 11

Neurons

Front 12

How do neural inducers work?

Back 12

They bind to BMP and permits neural fate.

Front 13

What is the fate of an animal cap in each of the following states:
Intact
Disassociated
Disassociated+BMP

Back 13

Intact- epidermis
Disassociated- neurons
Disassociated+BMP- epidermis

Front 14

The activation of SMAD, GATA and MSX is part of what type of induction?

Back 14

Epidermal induction by BMP

Front 15

The SMAD, GATA MSX pathways also inhibit what gene?

Back 15

SOX

Front 16

What is the purpose of the FGF pathway?

Back 16

Ultimately it is a neuron inducing pathway which activates SOX, stimulating other proneural genes.

Front 17

What factors contribute to the dorsalization of the neural tube?

Back 17

WNT and BMP

Front 18

What protein contributes to the ventralization of the neural tube?

Back 18

SHH

Front 19

The notocord affects the ventral or dorsal part of the neural tube?

Back 19

Ventral (floorplate)

Front 20

What happens to the neural tube if you remove the notocord?

Back 20

Failure to form ventral structurs such as floorplate or ventral motor neurons.

Front 21

T/F SHH is reliant on the notocord to induce ventral structures.

Back 21

False. SHH can induce ventralization without the notocord being present.

Front 22

High conc. of SHH produces _____ while low concentrations produce _____.

Back 22

Floorplate
motorneurons and interneurons in the neural tube.

Front 23

What are 2 organizers that induce head patterning and how do they work?

Back 23

Dickkopf and cerebrus function by inhibiting the WNT/BMP pathways.

Front 24

Emx2 and Pax6 are responsible for____

Back 24

Cortex patterning.

Front 25

Emx2 is primarily expressed in the ______region of the cortex.
Pax6 is primarily expressed in the ______region of the cortex.

Back 25

Posterior/Caudal

Anterior/Rostral

Front 26

Emx2 is promoted by_____and inhibited by_______
Pax2 is promoted by_____and inhibited by_______

Back 26

WNT/BMP....FGF
FGF.....WNT/BMP

This makes sense-WNT/BMP=Dorsalization, Emx2 is posterior of brain.

Front 27

Succinctly describe Delta/Notch pathway

Back 27

ASC drives expression of delta.
Delta is ligand for Notch.
Notch signals inhibitory of cascade for ASC.

Front 28

Central nervous system neurogenesis involves ____cells in the ________.

Back 28

Radial Glial Cells
Ventricular zone.

Front 29

What is the order of nervous system cell development?

Back 29

Neurons, Oligodendrocytes, Astrocytes

Front 30

What is the take home message from drosophila Sensory Organ Precursor?

Back 30

One a cell is fated for a specific purpose, it can inhibit all of the surrounding cells from having the same fate.

Front 31

Succintly describe the steps involved in neurogenesis.

Back 31

Radial glial cells divide in the ventricular zone to form neural progenitor cells.
The progenitor cells divide to form one Neural precursor.
The neural precursor migrates to the mantle zone where it differentiates into a neuron.

Front 32

Describe the role of Delta and Notch in the neurogenesis pathway.

Back 32

Delta-->migratory neurons (no notch)
Notch-->precursor glial cells
Precursor glial cells--->+More Notch=Astrocytes
--->-Less Notch= Oligodendrocytes

Front 33

Define intrinsic determination.

Back 33

Progenitor cells have a limited ability to produce certain neural subtypes because of transcription factors.

Front 34

Describe the pathway that allows neurons to be born before astrocytes

Back 34

Prenatal- open chromatin allows WNT activation of NGN1/2 which promotes neuronal fate and prevents astrocytic fate.
Postnatal- chromatin becomes methylated and saturated with PcG resulting in supression of WNT activation of NGN1/2 and ultimately promoting astrocytic fate.

Front 35

JAK-STAT, JAG1/2, CT-1,NFIA, and DNMT1 are all involved in what neural fate

Back 35

Astrocyte genesis

Front 36

T/F the neural progenitor is the same cell as the radial glial cell

Back 36

True

Front 37

Describe the histogenesis of neurons thru different regions of the cortex from early to late genesis.

Back 37

1. Ventricular zone
2. Migration to subplate and Cajal-Retzius region
3. Layer formation between subplate layers: Cortical plate.

Front 38

SLIT, ROBO, MIA, DCC, and netrin are what kind of signals? What do they accomplish?

Back 38

Motogenic, chemoattractive and chemorepuslive signals which move neuroblasts out of the ventricular zone toward the cortical plate.

Front 39

How does Reelin aid in neural positioning?

Back 39

It inhibits locomotion once neurons reach the marginal zone and promotes their detachment from radial glial cells.

Front 40

What type of radial migration dominates early, establishing, preplate and early cortical plate?
What type dominates late, establishing the 6 cortical layers and utilizing Reelin?

Back 40

Somatic Translocation
Glial Guided

Front 41

Are neurons deposited from inner cortical layers out or outer layers inward?
What is the order of layers from inside to out?

Back 41

Inside out.
654321

Front 42

What layer can give rise to both upper and lower cortical layer neurons,
And which can give rise to only upper layer neurons?

Back 42

Ventricular zone
Subventricular zone

Front 43

T/F. Younger neurons can develop in older zones via transplantation but older can only develop in older zones.

Back 43

True

Front 44

Most of the inhibitory neurons in the cortex originate from the ______

Back 44

Lateral/Medial Geniculate Eminence

Front 45

What would be the consequence of seperating the cortex from the Lateral geniculate eminence during development.

Back 45

Greatly reduced GABA (inhibitory) neurons.

Front 46

During migration, where must inhibitory interneurons first stop before reaching their final destination in the cortical layers?

Back 46

The ventricular zone-for positioning info

Front 47

Neurons and glia in the PNS arise from what region of the nueral tube? What structure of this region?

Back 47

The Dorsal region. (also cartiledge and bones and connective tissue)
Structure = Neural Crest

Front 48

Induction of neural crest cells to form PNS cells causes _______ to be born first and ______ to be born later.

Back 48

Neurons
Glial cells

Front 49

Crest cells exposed to high BMP and low Neuregulin are fated to become______.
Crest cells exposed to High delta and high Neuregulin are fated to become_____.

Back 49

Neurons
Glial cells

Front 50

Reelin is secreted by ____cells and causes neurons detach from ______.

Back 50

Cajal Retzius cells
Radial glial cells

Front 51

Describe succinctly the physical process occuring during cell polarity and the growth of an axon.

Back 51

Microtubles are polymerized by adding alpha beta tubulin dimers to the end of an extending neurite.
Schotastic process!

Front 52

Taxol is a drug which can induce _____ via_____.
It also produces _______ proteins

Back 52

Axon growth via microtubule stabilization.
Axon-specific proteins

Front 53

Contact Repulsion/Attraction as well as long range repultion/Attraction are all involved in ____________

Back 53

Axon Pathfinding.

Front 54

Describe the anatomy of the growth cone

Back 54

The microtubel axon comes to an enlarged lamelipodia which has extending fingers called filipodia which contain receptors that guide direction.

Front 55

What is the mechanism by which filipodia extend or retract to attractive or repulsive cues.

Back 55

Exocytosis and endocytosis. Either building more microfilaments by kinesin and dyenine or cannibilizing the that area of the growth cone.

Front 56

Netrin Receptors:
DCC alone is ____
DCC+UNC is _____

Back 56

attractive
Repulsive.

Front 57

Describe the calcium pathways in the growth cone. Describe it for attractive growth, then for repulsive.

Back 57

Attractive: DCC channels bind Netrin 1 which activates cAMP which opens calcium channels in the membrane and ER. Calcium influx results.
Repulsive: Dcc+UNC channels bind Netrin 1 which activates cGMP which blocks calcium channels on membrane and on ER. Calcium stays low.

Front 58

T/F cAMP and cGMP are antagonistic to each other.

Back 58

Tru

Front 59

Semaphorins can be found in the ___3__of the spinal cord and act as _______ to sensory neurons

Back 59

Ventral Horn, dermatomes, notocord
Chemorepellents

Front 60

The floorplate releases _______ which is _______to dorsal interneurons during migration.
The neurons are later repulsed by what chemorepulsive pair of ligand and receptor?

Back 60

Netrin, Chemoattractive
Slit/Robo

Front 61

What prevents the signals from the aural and visual receptors from cross-innervating the MGN and LGN

Back 61

There is an ephrin-receptor border that repels the axons from crossing over from the MGN to LGN.

Front 62

Semaphorines are _______ to dendrites

Back 62

Attractive

Front 63

Dendrites grow _____ axons grow ___-

Back 63

Up
Down

Front 64

What inducer is involved in drawing together axons and dendrites in the postsynaptic space?

Back 64

WNT--it also actively maintains the synaptic connections. At first it signals retrogradely from the post synapse to the presynapse, but eventually signals bidirectionally.

Front 65

What is the second signaling mechanism used in synaptogenesis besides WNT induction

Back 65

Glutamate signalling from the presynapse

Front 66

Dickkopf's inhibition of WNT in synaptogenesis leads to what?

Back 66

The decay of a synaptic connection by terminating WNT maintenance.

Front 67

Describe refinement of topography.

Back 67

One neuron with three processes eliminates two of them to focus on only one innervation.

Front 68

Describe refinement of convergence.

Back 68

Multiple neurons synapse on a single other neuron, but two retract and one remains.

Front 69

Describe refinement of postsynaptic compartment

Back 69

A single neuron innervating both basal and apical portions of another neuron narrows its focus to only one compartment.

Front 70

What are the five sources which influence neuron cell survival?

Back 70

Afferent sources (anterograde), target sources (retrograde), neighboring cell bodies (paracrine), blood born, and non-neural glial cells.

Front 71

What DRG survival factor was found to emminate from an implanted tumor to increase the size of DRG in a chick embryo?

Back 71

Nerve Growth Factor

Front 72

The release of BDNF is an example of how neuron _____can prevent cell death.

Back 72

Excitation/activation by potassium depolarization.

Front 73

What is the name of the process which removes rubbish from injury site in PNS?

Back 73

Wallerian Degeneration

Front 74

Phagocytosis in Wallerian degeneration is carried out principally by _______ and ______.

Back 74

Schwann cells
Macrophages (free floating)

Front 75

What is the name of the chain of Schwann cells which cross a site of injury to prepare for regeneration?

Back 75

Bands of Bungner

Front 76

What is the name of the myelinating cells in the PNS?

Back 76

Schwann cells

Front 77

What is the intracellular protein of astrocytes which radically changes in its expression following injury in the CNS?

Back 77

GFAP

Front 78

What process IS conserved in both the CNS and PNS after injury?

Back 78

Wallerian degeneration/phagocytosis. But to a lesser degree in the CNS.

Front 79

What is a CSPG?

Back 79

They chemically inhibit neurons from growing on them. They are deposited by astrocytes.

Front 80

_____ is a protein that is expressed on the sides of myelinating oligodendrocytes and prevent remyelination and regrowth of neurons in the CNS

Back 80

NOGO

Front 81

PTEN does what

Back 81

Its a tumor suppressor gene.

Front 82

Deletion of PTEN affects CNS recovery how?

Back 82

It improves recovery of CNS injury.