Construction of Neural Circuits Flashcards
What do cells exist as after neurogenesis?
Neuroblasts
What must a neurite contain to become an axon?
Par protien
What mediate travel of an axon?
Growth Cone
What is a growth cone?
Sheet like expansion called lamellipodium, containing filopodia
Describe filopodia
Dynamic cytoskeleton & express distinct receptors allowing for expansion & contraction as they search target
What is actin responsible for?
Movement of Lamellipodia/filopodia
What are microtubules responsible for?
Axon elongation
What is extracellular matrix?
Adhesive network or molecules outside of cells
What does extracellular matrix molecules activate?
Integrin receptors that control cell motility
What is CAM involved in?
Axon fasciculation
What are cadherins involved in?
Transition of a growth cone to a mature synapse
What happens when ephrins/Eph have favorable interaction?
Promotes adhesion & synaptogenesis
What happens when ephrins/Eph do not have favorable interaction?
Cleaved, preventing adhesion & synaptogenesis
What is chemoattraction?
Growth cones are moved
Chemorepulsion
Growth cones to not move
What do tropic molecules guide?
Growing axon toward a source
What do trophic molecules do?
Support neurons at their final site
Netrins interact with (blank) as chemoattracts
DCC
Netrins interact with (blank) as chemorepellent
Unc5
Netrins interact with extraceulluar matrix to promote?
Axon growth
What happens when netrin activates DCC receptors?
Bring cells to midline
When cells come to midline what happens?
Slit activates Robo
What does Robo activation prevent?
DCC receptors from being activated
Chemorepellant that impact brain repair following injury?
Molecules released by myelin in the CNS
What does the chemo-repellent Semaphorin do?
activate receptors on growth cones that lead to cytoskeletal depolymerization
What happens when Neuregulin 1 is released from presynaptic cells & activates ErbB on postsynaptic cells?
Promotes expression of post-synaptic proteins/receptors
At a synapse what happens when neurexins bind neuroligins?
-Promote adhesion
- Help to dock synaptic vesicles & cluster post synaptic proteins
- Hypothesized that different synapses use neurligins corresponding to specific neurotransmitter
What happens to axon or dendrites in the absence of synaptic partner?
Atrophy & die
How are synapse maintained?
Trophic factors
