Chemical Synapse 1 Flashcards
what is a feature of temporal summation
2nd PSP comes before the 1st PSP decays completed and 2nd PSP rides on back of first one
what determines temporal summation
postsynaptic time constant
what is a feature of spatial summation
arrival of 2nd input coincides that of the 1st
what are the two types of short term plasticity
faciliation
anti facilitaiton
what is a feature of facilitation
2nd PSP is bigger
2nd comes after 1st decays fully
what is the mechanism of facilitation
accumulation of ca2+ in presynaptic terminal
increase in releasable vesicles through auto-receptor
calcium channel facilitation
what are three characteristics of anti-facilitation
depression, decrement, fatigue
what is a feature of anti-facilitation
2nd PSP is smaller than the 1st PSP
what are the mechanisms of anti-facilitation
depletion of vesicles in presynaptic axon terminal
desensitisation of postsynaptic receptors
saturation of postsynaptic receptors
activation of autoreceptors
what are two forms of long term plasticity
ltp- long term potentiation
ltd- long term depression
where is LTP most commonly found
in the hippocampyus
where does LTP form
hebbian synapses
what is the main feature of LTP
after simultaneous firing, pre and post synaptic neurons have enhanced EPSPS
what is a model of LTP induction
schaffer collateral
ca1 pyramidial synapse
what is the main channel assoiated with LTP
NMDAR which blocked by Mg2+
what are the two phase of LTP
early and late
what is early phase ltp
ehancement of transmitter release, new AMPARs in postynsaptic membrane
increase glutamate affinity
what is late phase LTP
cAMP and cAMP kinase activated
CREB-1 protein phosphorylation
gene transcriptioin
new synapse
what is the feature of LTP at non hebbian synapses
LTP doesnt involve co activation of pre and post synaptic neurons
what is the mechanism of LTP at non hebbian synapses
activation of g proteins and protein kinases
what is the main feature of ltd
synaptic transmission becomes weaker over time
what is the mechanisms of LTD
at cerbrall parallel fibre synapse
internalisation and desensitsation of AMPARs