Lecture#7

Question 1

what do pioneer axons serve as

Answer 1

they use lots of environmental and chemical cues and signal where they should go

Question 2

what unique thing do pioneer axons set up

Answer 2

scaffolding

Question 3

what do pioneer axons rely on

Answer 3

environmental cues and signals

Question 4

what structure do developing axons have

Answer 4

a growth cone

Question 5

what kind of structure is a growth cone

Answer 5

a sensory and motor structure

Question 6

do growth cones move around

Answer 6

yes

Question 7

what kind of filaments do growth cones have

Answer 7

actin filaments

Question 8

what are the 2 structures that neurons have

Answer 8

axons and dendrites

Question 9

what kind of cytoskeletal protein do axons express

Answer 9

the cytoskeltal protein tau

Question 10

what kind of cytoskeletal protein do dendrites express

Answer 10

MAP-2

Question 11

How are axons and dendrites expressed

Answer 11

along an apical basal axis

Question 12

t/f the neurite that grows fastest becomes a dendrite

Answer 12

false , it becomes an axon

Question 13

do axons have more actin or mitcrotubules

Answer 13

they have more microtubulin

Question 14

if you reduce microtubulin stability what occurs

Answer 14

they become dendrites

Question 15

t/f axons have more microtubulin stability

Answer 15

true

Question 16

less microtubulinn stability means…

Answer 16

dendrite

Question 17

if you cut off an axon what will occur

Answer 17

a dendrite will grow quickly and turn into an axon

Question 18

can growth cones move around

Answer 18

yes

Question 19

list the 3 main regions of a growth cone

Answer 19

central core, filopodia , lamellipodia

Question 20

t/f there are lines of actin cables that are found in the lamellpodia

Answer 20

true

Question 21

is there is actin cable found at the tips of the lamellpodia

Answer 21

no there is actin monomer at the tip

Question 22

where does the sensory capibility of a growth cone come from

Answer 22

from the fillopodia

Question 23

do growth cones move fast

Answer 23

yes

Question 24

is actin found in the c or p zone

Answer 24

p zone

Question 25

are microtubles found in the p or z zone

Answer 25

in the c zone

Question 26

when filopedia binds to a receptor what will it allow it to do

Answer 26

it allows it to change direction/ retract

Question 27

t/f new filopedia is created everytime the growth cone moves

Answer 27

true

Question 28

what ion is an important second messenger are second messenger pathway

Answer 28

calcium

Question 29

will a ton of calcium make movement better

Answer 29

no, it needs to be at a set point

Question 30

what are 2 things that are important second messenger pathways

Answer 30

cyclic nucleotides and calcium

Question 31

through what kind of technique did we learn about growth cones

Answer 31

time lapse imaging

Question 32

how fast can fillopodia grow

Answer 32

1mm/day

Question 33

during growth , where are new microtubles added to axons

Answer 33

they are added to the distal end (tip) and the middle

Question 34

what does retroograde flow refer to

Answer 34

it refers to what actin filaments have

Question 35

actin also adheres to surfaces, what doe this help with

Answer 35

this adhesion helps with movement

Question 36

t/f growth cones are moving all the time

Answer 36

true

Question 37

t/f growth cones create new filapodia

Answer 37

true

Question 38

why are growth cones in a dynamic state

Answer 38

because they do not have the capping protein

Question 39

t/f growth cones are in a dynamic state

Answer 39

true

Question 40

where do growth cones grow

Answer 40

in the cracks/ stress fractures of dried collogen matrix

Question 41

do growth cones like + or - substrates

Answer 41

+

Question 42

if there are more adhesive substrates what kind of neurites are there

Answer 42

flatter/more neurites

Question 43

if there is a less adhesive substrate what kind of neurites are there

Answer 43

less neurites but they move faster

Question 44

can a substrate be too adhesive

Answer 44

yes

Question 45

can growth cones choose where they want to grow

Answer 45

yes

Question 46

a substrate that a neuron prefers depends on what

Answer 46

the intregrin substrate

Question 47

t/f all cells have integrin

Answer 47

true

Question 48

where are mauthener neurons found and where do they project to

Answer 48

they are found in the hindbrain and they project to the spinal cord

Question 49

what are the 4 catergories of cues

Answer 49

contact adhesion contact repulsion long range repellant long range attraction

Question 50

t/f growing axons follow the path of other axons

Answer 50

true

Question 51

what kind of molecules do neurons express

Answer 51

cell adhesion molecules

Question 52

if a bunch of neurons express the same kind of molecule what will happen

Answer 52

they will bundle up , this is is called fasiculation

Question 53

t/f if a bunch of axons in one area express the same kind of cam , they bundle which is called fasiculation

Answer 53

true :)

Question 54

do local or distant cues guide growth cones to the right place

Answer 54

it is a combo of the 2

Question 55

the neurite that grows the fastest becomes ..

Answer 55

the axon