Lecture 7 - Excitatory synaptic function

Question 1

Activation of postsynaptic ionotropic glutamate receptors, causes a
transient ……..of ion channels allowing net influx of cations,
generating an …… current

Answer 1

opening, excitatory

Question 2

…… glutamate receptors play a modulatory role in synaptic transmission

Answer 2

metabotropic

Question 3

name 3 disorders in which glutamate plays a role in learning and memory

Answer 3

epilepsy, schizophrenia, brain damage

Question 4

When the postsynaptic neuron is excitatory, the glutamatergic
synapse is usually found on which 2 locations of the excitatory cell?

Answer 4

spine or dendritic shaft

Question 5

give an example of a postsynaptic excitatory neuron where the glutamatergic synapse is found on the spine or dendritic shaft

Answer 5

hippocampal pyramidal cell

Question 6

When the postsynaptic neurons is inhibitory , the glutamatergic
synapse is usually found on which 2 locations of the inhibitory cell?

Answer 6

soma or dendritic shaft

Question 7

give an example of a postsynaptic inhibitory interneuron on which the glutamatergic synapse is found on the soma or dendritic shaft

Answer 7

paralbumin-positive interneuron

Question 8

name the 3 families of ionotropic glutamate receptors

Answer 8

AMPAR, KAINATER, NMDAR

Question 9

which two classes of ionotropic glutamate receptors are mostly co-localised at glutamatergic synapses where they mediate fast chemical synaptic transmission

Answer 9

AMPARs and NMDARs

Question 10

which class of ionotropic glutamate receptors open and close quickly and are responsible for the fast excitatory synaptic transmission in the CNS

Answer 10

AMPAR

Question 11

which 2 ions are AMPARs permeable to, which ion are some of them permeable to?

Answer 11

sodium and potassium, calcium

Question 12

name the 4 subunits which make up AMPARs

Answer 12

GluA1,2,3,4

Question 13

AMPAR activity can be regulated by second messenger cascades of which kinases?

Answer 13

PKA, PKC, CaMKII

Question 14

how many types of subunit do NDMARs have? what do they form therefore?

Answer 14

3, tetramers

Question 15

is the activation of NMDARs slow or fast?

Answer 15

slow

Question 16

the activation of NMDARs requires the binding of glutamate and which co-agonist?

Answer 16

glycine

Question 17

which 3 ions do NMDARs allow the entry of into the neuron?

Answer 17

sodium ,potassium ,calcium

Question 18

NMDARs are sensitive to ligands and…..

Answer 18

voltage

Question 19

at RMP, NMDARs carry little current as which ions block permeability to cations? how is this block relieved?

Answer 19

magnesium, relieved by depolarisation

Question 20

the flux of which ion through
NMDARs is thought to play
a critical role in synaptic
plasticity - the cellular
mechanism for learning
and memory?

Answer 20

calcium

Question 21

which glutamate receptors open first, AMPA or NDMA?

Answer 21

AMPA

Question 22

give an example of a NMDAR antagonist, making it have fast synaptic transmission

Answer 22

D-AP5

Question 23

give an example of an AMPAR antagonist giving it slow synaptic transmission

Answer 23

SYM2206

Question 24

…… and …….
receptors generate the large and early
component of EPSCs, whereas …….
receptors contribute to the late component
of the EPSCs

Answer 24

AMPA and KAINATE, NMDA

Question 25

how many transmembrane domains do metabotropic glutamate receptors have and which 2 termini?

Answer 25

7, intracellular c and extracellular n

Question 26

how many subtypes of metabotropic glutamate receptors are there which embody the 3 distinct functional groups?

Answer 26

8

Question 27

group 1 metabotropic glutamate receptors cleave PIP2 into which 2 products? which of these products diffuses into the cytoplasm and binds ER which releases calcium?

Answer 27

IP3 and DAG, IP3

Question 28

name the 5 effects of activating group 1 metabotropic glutamate receptors

Answer 28

calcium release from stores, PKC increase, homer protein release, inhibition of K+ (increases excitability), less negative membrane potential

Question 29

the increase of PKC activity caused by activation of group 1 mGluRs enhances the activity of which ionotropic glutamate receptor type?

Answer 29

NMDAR

Question 30

which protein is Important for trafficking mGluRs into and out of synapses and functionally connect mGluRs to iGluRs?

Answer 30

homer protein

Question 31

where are group 2 and 3 mGluRs located where they act as neuroprotective autoreceptors? what do they reduce in the terminal?

Answer 31

presynaptic terminals, reduce glutamate

Question 32

following which two events can excitotoxicity occur from glutamate destroying neurons?

Answer 32

trauma or hypoxia-ischaemia

Question 33

changes in synaptic efficiency can occur through which two forms? where do these occur in the brain-which part?

Answer 33

long term potentiation and long term depression, in hippocampus

Question 34

name the 3 pathways in hippocampal formation which display long term potentiation

Answer 34

perforant pathway, mossy fiber pathway, schaffer collaterals

Question 35

which 2 types of ionotropic glutamate receptors does the CA1 region have in the hippocampus (LTP)?

Answer 35

NMDA, AMPA

Question 36

when the calmodulin CaMKalpha2 is blocked does it stop or start long term potentiation?

Answer 36

stops it

Question 37

does self phosphorylation of CaMKalpha2 increase or decrease the duration of LTP?

Answer 37

increase

Question 38

Phosphorylation by CaMaKII causes conformational changes in which ionotropic glutamate receptor?

Answer 38

AMPAR

Question 39

LTP at schaffer collateral CA3 synapses is due to the postsynaptic influx of which ion and the activity of what?

Answer 39

calcium, CaM kinase

Question 40

LTP AT MOSSY FIBER (DG)--CA3 SYNAPSES IS DUE TO ......... CALCIUM INFLUX AND ......./.... PATHWAY

Answer 40

presynaptic, cAMP/PKA

Question 41

LTP – AMPARs ....... into the postsynaptic membrane LTD - AMPARs ...... from the postsynaptic membrane

Answer 41

insertion, removal

Question 42

growth or shrinkage of the spine from LTP/LTD occurs via the reshaping of what?

Answer 42

actin cytoskeleton

Question 43

to initiate gene transcription which protein must CaMKalpha2 bind?

Answer 43

CREB protein