Cellular and Molecular LTP Flashcards
High-frequency firing of synaptic inputs drives more ?
Glutamate release from the presynaptic terminal
What does glutamate bind to?
Glutamate binds to AMPA and NMDA receptors
What happens when the AMPA receptor ion channels open ?
The movement of charge depolarises the postsynaptic neuron
What happens when depolarisation of the postsynaptic neuron is sufficient ?
The magnesium is released from the channel of the NMDA receptor
What happens when the NMDA receptor ion channels open ?
Allows Ca2+ to enter the cell and trigger changes in synaptic strength
What is the composition of the Postsynaptic density (PSD) ?
- Receptors and ion channels
- Scaffolding proteins (e.g. PSD95)
- Kinases and phosphatases
- Cell adhesion molecules
- Structural proteins (e.g. actin)
What prevents LTP induction?
Introducing inhibitors of calmodullin or protein kinases into the postsynaptic
What does glutamate do during basal transmission ?
Glutamate activates only AMPA receptors
What does tetanic stimulation enable glutamate to active ?
NMDA receptors
Ca2+ ions entering through NMDARs activate ?
PKC or bind to CaM
The Ca2+/CaM complex activates ?
α-CaMKII
a-CaMKII autophosphorylation maintains ?
It’s active state
α-CaMKII and PKC phosphorylate
Transmembrane AMPA receptor regulatory proteins (TARPs)
What does activated α-CaMKII phosphorylate ?
Synaptic Ras-GTPase-activating protein (SynGap)
What does phosphorylated SynGap dissociate ?
Phosphorylated SynGap dissociates from PSD95
AMPAR/TARP complex binds to?
Free PDZ domains of PSD95
PKC and a-CaMKII phosphorylate ?
AMPA receptors
Phosphorylation of AMPARs increases ?
Their conductance
AMPA receptors are synthesised by ? and processed and sorted in ?
- AMPA receptors (AMPARs) are synthesised by ribosomes on rough endoplasmic
reticulum - Processed and sorted in the Golgi
Kinesin drives plus end directed transport of AMPAR-containing vesicles into ?
Dendrites along tubulin microtubules
Myosin drives local transport of AMPAR-containing vesicles into and out of ?
Dendritic spines along actin microfilaments
Vesicles fuse with the cell membrane within dendrites and spines to ?
Deliver AMPA receptors to the neuronal surface
AMPARs are retrieved into endosomes and sorted for ?
Degradation or recycling
Endosomal AMPAR transport by ?
Ca2+-dependent Myosin Vb
What is Myosin Vb ?
Myosin Vb is a motor protein
activated by an increase in
intracellular Ca2+
What is Synaptotagmin (Syt)?
Synaptotagmin is a Ca2+ sensor that triggers membrane fusion and exocytosis
What is the final journey of AMPARs ? and how ?
- To the PSD
- By surface diffusion
LTP induction at Mossy fibre synapse is ?
NMDAR-independent
An action potential activates VGCCs and triggers?
Glutamate release
Tetanic stimulation causes ?
A large increase in Ca2+
Ca2+ and Ca2+/CaM stimulate?
Adenylyl cyclase to make cAMP
cAMP stimulates?
cAMP-dependent kinase (PKA)
PKA phosphorylates ?
Substrates involved in exocytosis
Late LTP requires ?
Protein synthesis and protein kinase A (PKA)
PKA translocates to ? and phosphorylates ?
PKA translocates to the nucleus and phosphorylates CREB
CREB (cAMP response element-binding protein) activates ?
Transcription of genes to form new synapses
