Neuro12 - 18 Flashcards
Characterise synapse formation
Competitive, not all persist, not all made the same way
What is synaptogenesis dependent development?
Target relies on innervation to differentiate
What is synaptogenesis independent development?
Targets present before innervation
Outline overall synaptogenesis
Growth cone turns into presynapse - develops postsynaptic specialisations
What dictates synaptic sites?
Approaching growth cone talks to target
How was growth cone talking determined?
Sniffer pippette - membrane bound receptors outwardly facing detect electrical activity increasing with proximity
What occurs during NMJ development?
Diffuse distribution develops into more focussed - 1,000um > 10um
Expression of what increases around NMJs during development?
Increase synthesis of the subunits required for the acetyltransferase receptor
What induces receptor synthesis?
ARIA - 42kD protein, released by motoneurons, increases produciton of AChR epsilon subunit
What is neuregulin?
Can increase NMDA receptors in developing cerebellum
What receptors demonstrate receptor clustering?
AChR, glycine, GABA, glutamate
What evokes receptor clustering?
Denervated and destroyed muscle - NMJs form where synaptic basal lamina persists
What proteins are important in receptor clustering?
Agrin, MUSK and rapsyn
What model system is used to investigate clustering factors?
Torpedo californica
What does agrin do?
Stimulates clusters of receptors
