The roll of cell death and neurotrophies in the survival and shaping of neurons Flashcards
What was the victor Hamburg experiment
Shows that the target size was important using chicks
What happens if you add extra limb buds
Far more motor and sensory neurons survive
What does the correaltion in the Victor Hamburg experiment suggest
That the target tissue may be providing some sort of trophic response
Whats the neurotrophic factor hypothesis
-Neurons are produced more than need and excess is eliminated over time
-Neurotrophic factors can emanate from targets to promote survival according to tissue size
What are the two kinds of cell death
Apoptosis and necrosis
What other elements help control cell death
BAX (bcl-2 associated)
Caspase 9 (cysteine - aspartic acid protease)
What are the two classes of gene/ protein
Anti-apoptotic: loss leads to massive cells death (prevents cell death)
Pro-apoptopic: loss leads to excess cells (normally required for cell death)
What are the two classes of caspases
Inhbitor caspase (caspase 9) and executioner (caspase 1)
What did implanted sarcomas provoke
Selective survival of sensory and sympathetic neurons
Whats a diffusible growth factor
A protein purified from tumour cells
What complex was NGF discovered by and what was the active component
7S-NGF=a2by2
Active component: beta-NGF
What is NGF
Both tropic and trophic. It can lead to survival and control where things go
What happens when NGF binds to receptors
It gets internalised and transported to the soma-retrograde support
What do DRG cell bodies do
Take up NGF and the receptor (TrkA)
What does NGF activate
MAP kinase pathway to regulate transcription in the nucelus
It activates the Akt pathway to inhbit apoptosis and promotes cell movement
