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19 Cards in this Set
- Front
- Back
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which neurotransmitter is involved in potentiation in Aplysia?
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serotonin (5-Ht)
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what is the serotonin receptor, and signal cascade?
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Gpcr-Gs -> cAMP, activates Protein Kinase A (PKA)
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what does PKA fosforylate? and where does this lead to?
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PKA fosforylates a potasium channel (K+) and calcitonin, both facilitating endocytosis (either through higher activation of VOCC's, or a more potent peptide)
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what are the proteins produced through a supralinear responce?
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NT-synthesis enzymes, exocytose-machinery proteins, receptors and hydrolase*
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what is the function of hydrolase?
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it keeps CREB activated by breaking down the regulatory subunit of PKA so the catalitic subunit can not bind again and become inactive.
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how can early LTP be induced? and how long does it last?
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by giving 1 100hz train, lasts for a few hours
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how can late LTP be induced and how long does it last?
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by giving 4 100hz trains, lasts for a few days
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which receptor has a Mg2+ block? and how can it be lifted?
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the NMDA receptor. it can be lifted by a strong depolarisation of the membrane (through a strong EPSP or back propagation)
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name some test's or results that support the NMDA-LTP theory.
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add a NMDA antagonist (AVP), blocking LTP. receptor knock out (cre-loxP) overexpression of NMDA leads to longer LTP
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what is the basic effect of a backpropagated action potential?
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VOCC's will open, and the Mg2+block is removed
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what does active CaCaMK do?
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it fosforylates proteins, aswell as adenalyn cyclase, producing cAMP and so activating more PKA which canf fosforylate other proteins. thereby it also fosforylates the AMPA-R, making it more sensitive (early LTP)
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which fosforylation mediates early LTP?
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the fosforylation of the AMPA receptor. making it more sensitive to glutamate. and giving it a higher conductance for Na+
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what are the two CaMK isoforms, and what is their function?
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CaCaMK II, and IV (late LTP).
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what are the AC isoforms and their functions?
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AC I, and VIII, double knockout=no late LTP, so compensation takes place
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what is the effect of AC over expression?
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gives improved memory
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how can over expression be identified?
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with a reporter gene, located close to the over expressed gene.
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what are the dimers present in the AMPA-r?
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always an R2 dimer, with R1,3 or 4
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what are the fosforylation sites on the GluR1 subunit in the AMPA-r? and which one is necassery for LTP?
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p5831=CaCaMK fosforylation site p5845= PKA fosforylation site. the CaCaMK is needed for LTP
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which receptor is localised in the spine after LTP?
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the GluR1 receptor
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