lecture 10- growth cone responses Flashcards
what are the three different sections of a growth cone and do they contain F-actin or microtubules
central= microtubules
transitional=F-actin
peripheral=F-actin
what is the molecule in growth cones that forms a web structure
lamella
what is the molecule in growth cones that is made of polarised actin bundles
filopodium
describe the movements of F-actin and tubulin in a resting growth cone
F-actin treadmills (moves but doesnt go anywhere)
tubulin is dragged sporadically into filopodia
what happens to F-actin and tubulin when a growth cone comes into contact with an attractive cue
F-actin treadmilling slows and F-actin accumulates
the filopodium is stabilised and tubulin is dragged to back of filopodium
do growth cones still attach when they have collapsed
yes, they just dont grow
what happens to the F-actin when a growth cone is collapsed
destabilised
what are semaphorins
a family of inhibitory guidance cues
what are the four tactics of axon guidance
contact attraction
contact repulsion
chemoattraction
chemorepulsion
which tactics tell axons which way to go
chemoattraction/repulsion
why do axons prefer to grow in laminin over collagen
they prefer to grow on less ‘sticky’ substrates
what is laminin and how does it affect axon guidance
growth promoting extracellular matrix protein
it is permissive(allows growth) but not instructive(doesnt dictate direction)
how are Ephs and Ephrins expressed
reciprocally
where does chemoattraction come from
netrin in the floor plate
where does chemorepulsion come from
BMPs in the roof plate
