LTP and memory

Question 1

passive avoidance task

Answer 1

traning mice: kept in lit compartment, if enter dark compartment - receive a footshock
testing mice: animal stays in lit compartment becasue the dark=danger
this requires hippocampus (form memories) increase in synaptic transmission

Question 2

pharmacological block of NMDA R

Answer 2

infuse NMDA R ant into ventricles - mice cannot find platform during MWM
LTP/LTD is blocked
LTP needed for spatial memory

Question 3

what is a limitation of using pharmacological drugs to study LTP

Answer 3

only available for a few proteins

Question 4

what can be used to study LTP instead of pharmacological drugs

Answer 4

genetic manipulations

1) gene KO
2) KO restricted to specific brain regions
3) KO restricted in time
4) point mutation
5) protein overexpression

Question 5

KO of a-CamKII & point mutation at T286

Answer 5

CA1-LTP and spatial learning is impaired
no autophosphorylation due to no -OH group

severely impaired CA1-LTP memory formation

Question 6

de novo mutant of CamKII

Answer 6

parents are heterozygous and do not have the mutant
DeNovo CamKII mutants cause intellectual disability in humans (loss/gain of functions)

Question 7

enhancing LTP by overexpression of the NR2B subunit

Answer 7

lowers activation threshold
increases Ca2+ permeability
improves spatial learning

Question 8

PKMzeta and ZIP (zeta inhibitory peptide)

Answer 8

PKMz - maintains LTP by preventing AMPA R endocytosis
ZIP - inhibits PKMz - erases spatial memory and enters shock zone

Question 9

why is there only a correlation between LTP and memory

Answer 9

no protein is dedicated to memory
pharmacological and genetic manipulations have a side effect

Question 10

KO of NR1 subunit at the CA1 synapse

Answer 10

blocked CA1 LTP (impaired spatial memory formation)

Question 11

NR1

Answer 11

encoded by GRIN1 gene
obligatory subunit for all NMDA R

Question 12

KO of NR1 subunit at the CA3 synapse

Answer 12

Full cues and partial cues in MWM protocol
partial cues cause less memory
CA3-LTP not important for spatial memory but required for pattern completion

Question 13

DG restricted KO of NR1

Answer 13

not required for spatial memory but required for pattern separation

Question 14

behavioural training

Answer 14

tone wait shock
does not induce LTP at every synapse

eyeblink conditioning - enhanced synaptic transmission

Question 15

novel objection configuration and LTD

Answer 15

LTD is important for item-place memory

Question 16

pattern separation

Answer 16

new memories use the framework of previous memories
LTD removes superflous elements
if no LTD, memories overlap and there is no pattern separation

Question 17

role of FMRP & TSC2

Answer 17

regulates protein synthesis at the spines
activates PKC and protein synthesis
in autism there is decreased protein synthesis, impaired mGluR induced LTD and pattern separation

Question 18

vestibu-ocular reflex VOR

Answer 18

keeps vision stable during head movement
semi-circular canals contain fluid (act as motion detectors)
vestibuli nuclei in the BS (HCs receive signals)
cranial nerves (III,IV,VI) control eye movement

Question 19

Blocking LTD at pf-PC synapses

Answer 19

impaired motor learning
in some mutants, LTD is not essential for motor learning