Exam 1: Lecture 3

Question 1

____ is acquisition of glial-class identity

Answer 1

gliogenesis

some radial glia progenitors give rise to glia after neurogenesis

Question 2

shh controls pattern of specification in neural progenitors. This sets up ___ ___

Answer 2

progenitor domains

Question 3

Motor neurons from __ domain

Answer 3

Olig2

Question 4

Spinal interneurons derive from ___ and ____ domains

Answer 4

Nkx2.2

Pax6-Irx3

Question 5

Do motor neurons differentiate at higher/lower rate than interneurons

Answer 5

higher rate

Question 6

___ induces expression of Olig2, which directly promotes neuronal differentiation in motor neuron progenitors by suppressing the expression of HES GENES (negative regulators of neuronal differentiation)

Answer 6

Shh

Question 7

Genetic program that defines the identity of corticospinal neurons will have

Answer 7

instruction for brain region, structure, class of neuron, subtype

Question 8

Broad specification of progenitor domains by

Answer 8

extracellular morphogens

Question 9

Different progenitor domains give rise to different

Answer 9

classes of neurons

Question 10

FGF- __ neuron

BMP2,4 ___ neuron

Answer 10

CNS neuron

PNS neuron

Question 11

Waddington’s binary decisions

Answer 11

bifurcates into different grooves goes the marble

Question 12

What is the problem with canalization? Can we change landscape?

Answer 12

Pluripotent reprogramming
Direct conversion

YES!

Question 13

Why is reprogramming neurons cool?

Answer 13

make specific types for drug test and disease model

patient derived neurons

replacement therapy

Question 14

Directed differentiation into a specific type of neuron/glial cell:

Genetic programs encoding neuron/glia ______

Answer 14

subtype identity

need to know this to make desired cell

Question 15

When Caudal signals (RA/some wnts) are gone…

Answer 15

Go rostral

Question 16

If ventralizing signals blocked

Answer 16

dorsal telencephalic progenitors induced

EXCITATORY = dorsal

Question 17

Add ventraling signals

Answer 17

INTERNEURONS = ventral (GABA)

Question 18

Specific combinations of _____________ _______ can be added to further specify neuron identity (DA< SE, Cholinergic)

Answer 18

transcription factors

Question 19

What factors bring somatic cell back to pluripotent state?

Answer 19

Yamanaka factors

Question 20

Advantages of iPSCs

Answer 20

limitless source of neurons

used as patient specific therapy -lower risk of rejection

reduce ethical issues

Question 21

Cons of iPSCs

Answer 21

pluripotent origin- risk of tumor formation

Question 22

Pros of directly reprogrammed cells

Answer 22

reduced tumorigenic potential

patient-specific lower risk of graft rejection

reduced ethical issues

Question 23

Cons of directly reprogrammed cells

Answer 23

finite number of neurons can be produced protocols efficiency remains low

Question 24

Disk model:

no hierarchy

Answer 24

pluripotent state just one of possible states

can be bypassed

extrinsic factors tilt the disk and transcription factors guide

Question 25

Can pericytes from adult human brain (biopsy) reprogram into neurons?

Answer 25

Yes

Question 26

The process by which neurons send out axons to reach their targets

Answer 26

Axon navigation

Question 27

The process by which axons select their target structure and specific target neurons

Answer 27

Target selection

Question 28

The process by which synaptic targets are recognized by growing axons, and initial contact and communication between neurons is established. Usually connections exuberant during early development

Answer 28

Synapse formation

Question 29

The process by which synaptic connections refined. Unnecessary connections eliminated and function circuits strengthen

Answer 29

Circuit maturation and entrainment

Question 30

Growth cone: ___-zone: actin-rich lamellipodia and filopodia ___-zone: microtubule more stable

Answer 30

P zone C zone

Question 31

Main molecular sign posts for growth cone?

Answer 31

1) Guide post cells 2) Long-range cues (attractants/repellants) 3) short-range cues (adhesion or repulsion)

Question 32

cells important decision points in axon's route

Answer 32

Guidepost cells

Question 33

Navigate a much simpler environment as tissue is less developed They served as trail blazers or scaffold for other axons that navigate the pathway after them. What are they?

Answer 33

Pioneer axons

Question 34

Short range REPULSION

Answer 34

actin depolymerization

Question 35

Short range ATTRACTION

Answer 35

microtubule stabilization

Question 36

short range cues provide ___ for axon growth

Answer 36

substrates

Question 37

different types of neurons shows preference for a particular ECM protein depending on _____ ECM proteins promote ____ ___

Answer 37

Receptors axon growth

Question 38

CAMS signals 1) Guidepost cells 2) axon _____

Answer 38

fasciculation

Question 39

Attractant or repulsion: NGF

Answer 39

attractant

Question 40

Attract/repulse: Netrin/Ephrin/Wnt

Answer 40

both

Question 41

Semaphorin/slit

Answer 41

repellant

Question 42

How can some attract and repulse

Answer 42

cAMP levels and receptor type

Question 43

The order of signals in sequence influences navigation. What is this called?

Answer 43

spatiotemporal regulation

Question 44

Desensitization to signals by ___ of receptors or other interactions

Answer 44

degradation

Question 45

Commisural axons (crossing signals)

Answer 45

Robo receptors Slit High level ROBO3A

Question 46

How does crossing work

Answer 46

ROBO3A inhibits ROBO1 so cross to get to DCC

Question 47

After crossing

Answer 47

Robo1 is like: you ain't going back And Robo3B is like: yas girl And slit is on this team too

Question 48

Can growth cone do stuff independent of soma?

Answer 48

Yep

Question 49

How does cell solve length of axon problem, cause the stuff gotta get there?

Answer 49

mRNA transported and stored at tip of axons/dendrites waiting for translation when is needed to meet immediate demand

Question 50

in growth cone, we got local ___ local ___ and local ___

Answer 50

local translation local mRNA splicing local regulation of cAMP/cGMP levels

Question 51

Do axons growth slower or faster when fasciculate together

Answer 51

faster

Question 52

What is the defasciculating signal in motor neurons?

Answer 52

beat-1a

Question 53

Branches usually formed when the leading GC

Answer 53

pauses

Question 54

Growth factors usually make axons

Answer 54

branch and grow toward target area

Question 55

The autonomous mechanisms in GC make possible to interpret different signals by GC in

Answer 55

same axon

Question 56

Matching gradients of expression of ligands in target area, and ligand receptors in axons, established what

Answer 56

topographic map

Question 57

Activity dependent | mechanisms in final targeting step reflect

Answer 57

cell specific targeting

Question 58

When growth cone at location

Answer 58

1) filopodia retract 2) GC pre and post membrane tightly apposed 3) vesicles add membrane to immature synapse 4) vesicles release progressively recruits receptors and proteins to postsynaptic density

Question 59

Connections keep and refined by

Answer 59

activity dependent mechanisms

Question 60

monocular neurons

Answer 60

layer 4