Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BMS249 DEVELOPMENTAL NEUROBIOLOGY > MECHANISMS OF AXON GUIDANCE 2 AND 3 > Flashcards

MECHANISMS OF AXON GUIDANCE 2 AND 3 Flashcards

1
Q

POLARITY IS ESTABLISHED AS NEURONS ARE …….

A

BORN

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

……… IN ENVIRONMENT INFLUENCE NEURITE SLECTION

A

CUES

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

WHAT REGIONS MAKE UP THE ANATOMY OF A GROWTH CONE

A

CENTRAL
TRANS
PERIPHERAL

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

THE CENTRAL REGION OF A GROWTH CONE IS MADE UP OF

A

MICROTUBULES

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

THE TRANS AND PERIPHERAL REGIONS ARE MADE UP OF

A

F ACTIN

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

WHAT IS A FILOPODIA

A

MEMBRANE PROJECTIONS THAT EXTEND OUTWARDS FROM THE GROWTH CONE

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

WHAT IS A LAMELLOPODIA

A

AN ACTIN MESH BETWEEN THE FILOPODIA

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

IN FILOPODIA THE ACTIN BUNDLES ARE ………………………… TO FORM LARGER ……………….OF NARROW EXTENSIONS

A

POLARISED

BUNDLES

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

IN LAMELLA THE ……………. BUNDLES ARE ……………. LINKED INTO A NET.

A

ACTIN

CROSS

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

F ACTIN…………………….. IN A RESTING GROWTH CONE

A

TREADMILLS

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

WHAT IS TREADMILLING

A

F ACTIN MOVES FROM THE PERIPHERY TO CENTRE WHERE IT BREAKS DOWN TO REJOIN THE TIP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

IN THE RESTING GROWTH CONE, TUBULIN IS DRAGGED SPORADICALLY INTO THE ……………………… - WHEN THE …………………. CONE COMES INTO CONTACT WITH AN ATTRACTIVE ………….., THIS BECOMES MORE ………………

A

FILOPODIA
GROWTH
CUE

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

THE GROWTH CONE ……………….. IN THE PRESENCE OF A CUE

A

REORGANISES

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

HOW DOES THE GROWTH CONE REORGANISE IN THE PRESENCE OF A CUE

A
  1. F ACTIN TREADMILLING SLOWS AND ACCUMULATES

2. ACCUMULATION STABILISES THE FILOPODIUM AND DRAGS MICROTUBULES INTO THE BACK OF THE FILOPODIUM

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

WHAT CAN AN ATTRACTIVE CUE BE COMPARED TO

A

ACTS AS A MOLECULAR CLUTCH IN ORDER TO PROPEL THE GROWTH CONE FORWARD

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

AN …………-TUBULIN LINK PULLS MICROTUBULES IN THE WAKE OF THE EXTENDING FILOPODIA

A

ACTIN

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

GROWTH CONES CAN BE ……………………… AND ……………………. BY CUES

A

REPELLED

ATTRACTED

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

WHAT STRUCTURALLY HAPPENS TO THE GROWTH CONE UPON REPULSION BY A CUE

A

THE GROWTH CONE COLLAPSES

THERE IS A DECREASE IN F ACTIN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

WHEN MIXTURES OF DIFFERENT NEURONAL TYPES ARE IN CULTURE, WITH WHAT NEURONAL TYPES THEY SEEM TO FASCICULATE WITH

A

THEIR OWN KIND

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

WHAT ARE SEMAPHORINS

A

A FAMILY OF INHIBITORY GUIDANCE CUES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

WHAT ARE THE MAIN TYPES OF SEMAPHORINS FOUND IN THE GRASSHOPPER EMBRYO LIMB

A

MEMBRANE BOUND

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

WHAT HAPPENS TO THE AXONS OF MICE THAT LACK SEMA3

A

AXONS STRAY INTO THE WRONG TERRITORIES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

WHAT IS THE FUNCTION OF SEMAPHORINS

A

CAN CHANNEL AXON GROWTH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

ALTHOUGH SEMAPHORINS CHANNEL AXON GROWTH WHAT IS STILL ALSO NEEDED FOR AXONAL GROWTH

A

PERMISSIVE FACTORS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
AXON CANNOT .................. WHERE THEY CANNOT ........................ BUT THERE IS NO LINK BETWEEN STRENGTH OF ............................ AND AMOUNT OF AXON GROWTH
GROW ATTACH ADHESION
26
HOW CAN YOU MEASURE ADHESION
WHAT SPEED OF CENTRIFUGE IT WITH DETACH
27
THERE IS NO LINK BETWEEN STRENGTH OF ADHESION AND AMOUNT OF AXON GROWTH - GIVE AN EXAMPLE
COLLAGEN HAS HIGHER ADHESION BUT LAMININ HAS HIGHER OUTGROWTH
28
'COLLAGEN HAS HIGHER ADHESION BUT LAMININ HAS HIGHER OUTGROWTH' WHAT CAN YOU CONCLUDE FROM THIS
GROWTH CONES NEED SUBSTRATES PERMISSIVE FOR GROWTH, ATTACHMENT IS NOT ENOUGH
29
EVEN IF A GROWTH CONE IS ..................., IT STILL ATTACHES TO A REPELLANT AXON
REPELLED
30
PERMISSIVE FACTORS CAN ................... SUBSTRATE PATHS IN THE EMBRYO. LAMININ PROMOTES GROWTH IN THE OPTIC NERVE BUT IT DOES NOT ...................... THE .......................... OF GROWTH, ONLY THAT IS CAN ................... THERE
DEFINE DICTATE DIRECTION GROW
31
WHAT EFFECT DOES BLOCKAGE OF A LAMININ RECEPTOR DO
SLOWS GROWTH BUT DOES NOT CHANGE THE DIRECTION
32
................... OF LAMININ ALSO DO NOT DIRECT AXON GROWTH. IN THIS WAY LAMININ IS ......................... BUT NOT ..............................
GRADIENTS PERMISSIVE INSTRUCTIVE
33
AXON GROWTH IS A BALANCE BETWEEN PERMISSIVE (CONTACT ..............) AND ......... .........................(CONTACT REPELLANTS) HOWEVER DIRECTION IS SIGNALLED BY ....................... ATTRACTION/REPULSION
ATTRACTION NON PERMISSIVE CHEMO
34
WHAT ARE EPHRINS
NON PERMISSIVE FACTORS USED IN EARLY PATTERNING AND TO GUIDE AXONS
35
EPHRINS ARE CELL ...................... MOLECULES DETECTED BY ............... THESE CAUSE ...................... BETWEEN CELLS WHICH HELPS TO .................................. DISCRETE DOMAINS. LATER IN DEVELOPMENT THEY ARE USE TO KEEP ................. OUT OF SPECIFIC AREAS.
``` SUFACE EPHS REPULSION COMPARTMENTALISE AXONA ```
36
KEY PATTERNING ...................... SECRETE LONG DISTANCE ..................... MOLECULES CHEMO ATTRACTANTS AND REPELLANTS
ORGANISERS | GUIDING
37
IF YOU TAKE A DORSAL SPINAL CORD (FLOOR PLATE) EXPLANT AND PLACE IT ECTOPICALLY, AXONS MOVE TOWARDS THE FLOOR PLATE WHAT DOES THIS SUGGEST
SUGGESTS THERE IS A CHEMOATTRACTANT IN THE FLOOR PLATE
38
CELL (SUCH AS THE FLOOR PLATE) EXPRESSING THE .................... GENE CAN TUEN COMMISSURAL AXONS
NETRIN
39
WHAT PROTEINS IN THE FLOOR PLATE CAN REPEL COMMISSURAL AXONS
BMPS
40
LONG AND ............... RANGE CUES WORK ...................... TO GUIDE AXONS TO THEIR TARGETS EG GRASSHOPPER ............ SUGGESTS A GRADIENT OF SEMA2 DIRECTS TI1 TOWARDS THE BODY WHILE SEMA 1 STOP AXONS FROM STRAYING
SHORT | TOGETHER
41
COMMISSURAL AXONS ARE GUIDED BY ............................. FACTORS IN THE ROOF PLATE AND .................... PLATE, BMP7 AND .................... RESPECTIVELY.
CHEMOTROPIC FLOOR NETRIN
42
BMP7 IS EARLIER USED TO ........................ THE CELL TYPES OF THE .................. CORD, ANTAGONISING .............. THIS SUGGESTS FACTORS MAY BE RE USED FOR ................... GUIDANCE
PATTERN SPINAL SONIC HEADGEHOG AXON
43
WHAT HAPPENS WHEN NETRIN IS KNOCKED OUT
AXON GUIDANCE IS DISRUPTED BUT SOME C AXONS STILL MAKE IT TO THEIR DESTINATION
44
WHY DO SOME AXONS STILL REACH THEIR TARGET IS NETRIN HAS BEEN KNOCKED OUT
BECAUSE SONIC HEDGEHOG ALSO GUIDES AXONS
45
WHAT WILL A SMOOTHENED KNOCK OUT HAVE AFFECT ON
SMOOTHENED IS PART OF THE SHH PATHWAY | THEREFORE THIS WILL DISRUPT AXON GUIDANCE
46
HOW CAN YOU GET TISSUE SPECIFIC DELETION OF A GENE
USE OF CRE RECOMBINASE AND LOX P
47
EXPLAIN METHODOLOGY OF TISSUE SPECIFIC DELETION OF A GENE
1. BACTERIOPHAGE P1 ENCODES CRE RECOMBINASE THAT CAN BE INSERTED INTO HOST GENOME 2. CRE RECOMBINASE BINDS TO LOXP (A SPECIFIC 34 BASE SEQUENCE) WHICH IS CAN CUT AND BIND TO ANOTHER LOXP 3. WE CAN SPECIFICALLY DELETE DNA BETWEEN THESE SEQUENCES - FLOXING 4. HOMOLOGOUS RECOMBINATION - CROSSING A MOUSE WITH A FLOXED ALLEL AND A MOUSE WITH A CRE UNDER A TISSUE SPECIFIC PROMOTER WILL GIVE A MOUSE WITH NORMAL EXPRESSION EXCEPT FOR IN THE TARGET TISSUE
48
AXONS REPROGRAM WHEN ..................... POINTS ARE ENCOUNTERED. AFTER TRANSIT OF THE MIDLINE, C AXONS LOSE .................................. TO ..........................
CHOICE RESPONSIVENESS NETRINS
49
POST CROSSING, AXONS BECOME SENSITIVE TO SOMETHING ........................ IN THE FLOOR PLATE. THERE IS ....................... OF NETRIN SENSITIVITY AND SENSITIVITY NOW TO ...................................... AND SLITS. THESE ARE EXPRESSED IN THE .......................... PLATE AND .................... SPINAL CORD CREATING A CHANNEL THROUGH WHICH C ................... CAN GROW. THE FLOOR PLATE HAS ..................................... THE AXONS.
``` INHIBITORY LOSS SEMAPHORINS FLOOR VENTRAL AXONS REPROGRAMMED ```
50
WHAT DETERMINES WHETHER C AXONS CROSS OR NOT AND WHAT PREVENTS RECROSSING
ROBO (ROUNDABOUT) | COMM (COMMISSURELESS)
51
WHAT IS ROBO
RECEPTOR FOR SLIT
52
WHAT IS THE ACTION OF ROBO
WHERE ROBO IS EXPRESSED AT HIGH LEVELS ON AXONS THAT DO NOT CROSS THE MIDLINE
53
WHAT OCCURS IN ROBO MUTANTS
ROBO MUTANTS CANNOT DETECT SLIT AND THEREFORE KEEP CROSSING THE MIDLINE
54
WHAT IS COMM
COMM IS EXPRESSED ONLY IN AXONS THAT NORMALLY CROSS THE MIDLINE
55
WHAT HAPPENS TO A COMM MUTANT
AXONS DO NOT CROSS THE MIDLINE AND ARE LONGITUDINAL ONLY
56
FORCED COMM EXPRESSION RESULTS IN WHAT
A PHENOTYPE THAT MATCHES THE ROBO MUTANT
57
WHAT CAN BE SAID ABOUT FORCED COMM EXPRESSION IN CONCLUSION
COMM CONTROLS ROBO
58
HOW DOES COMM CONTROL ROBO
COMM CONTROLS A TRAFFICKING PROTEIN REACHING THE CELL SURGACE TO THAT THE GROWTH CONE CANNOT RECEIVE SLIT INHIBITORY SIGNALS BEFORE CROSSING
59
COMM AND ROBO ARE NOT FOUND IN VERTEBRATES, WHAT OCCURS IN VERTEBRATES INSTEAD
IN VERTEBRATES ROBO=ROBO1 BUT IT IS EXPRESSED BEFORE AND AFTER CROSSING THERE IS NO COMM, ONLY ANOTHER ROBO LIKE PROTEIN, RIG 1 THAT APPEARS TO BLOCK ROBO1 UNTIL THE MIDLINE IS CROSSED
60
FOLLOWER AXONS USE THE ....................... SCAFFOLD. THEY MUST STAY ON AND GET OFF AT THE RIGHT PLACE. THIS IS DONE BY ...................... BINDING BY CELL ....................... MOLECULES. FASCICULATION AND DEFASCICULATION IN FLIES IS CONTROLLED BY ..........................2. BEAT PROTEIN CAN ALSO CAUSE ..........................
``` PIONEER HOMOPHILIC ADHESION FASCICULIN DEFASCICULATION ```
61
OVEREXPRESSION OF FASCICULIN 2 CAUSES WHAT
AXONS TO MISS THEIR TARGETS
62
WHAT ARE THE TWO TYPES OF TARGET SELECTION
DISCRETE (CELLULAR) | TOPOGRAPHIC (MULTICELLULAR)
63
IN DISCRETE TARGETS, ABLATION OF THE TARGET MUSCLES LEADS TO WHAT
FAILURE OF THE MOTOR AXON TO LEAVE THE TRUNK
64
THE TARGETS SECRETE CUES THAT PROMPT THE AXONS TO LEAVE THE TRUNK AND DEFASCICULATE TO THEIR TARGET. WHAT ARE EXAMPLES OF THE CUES.
NETRIN | FASCICULIN 3
65
IN TOPOGRAPHIC MAPS, ................................. NEURONS SEND .................. TO NEIGHBOURING SITES TO MAINTAIN ORDER.
NEIGHBOURING | AXONS
66
THERE ARE TWO THEORIES FOR TARGETS BY SPERRY WHAT ARE THEY
1. EACH AXON HAS A SPECIFIC LABEL FOR EACH TARGET | 2. A COORDINATE SYSTEM OF GRADIENTS OF SIGNALLING MOLCEULES OF LONGITUDE/LATITUDE READ BY RECEPTORS OF TARGET
67
WHICH OF SPERRY'S TWO TARGET THEORIES WAS CORRECT
MODEL 2
68
HOW CAN WE SHOW MODEL 2 TARGET SELECTION THEORY WAS CORRECT
THE STRIPE ASSAY
69
WHAT IS THE STRIPE ASSAY
CELLS FROM THE POSTERIOR TECTUM MAKE A NON PERMISSIVE FACTOR THAT REPELS TEMPORAL RETINAL AXONS TEMPORAL AXONS AVOID STRIPES OF THE POSTERIOR TECTUM
70
WHAT IS THE INHIBITORY FACTOR CAUSING STRIPES IN THE POSTERIOR TECTUM
EPHRINS A2/A5 TO RECEPTOR EPH A3
71
WHAT CAN WE CONCLUDE ABOUT THE STRIPE ASSAY
NON PERMISSIVE REPELLANT FACTORS CAN BE INSTRUCTIVE TO FORM TOPOGRAPHIC MAPS

BMS249 DEVELOPMENTAL NEUROBIOLOGY (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions