Lecture 6 Flashcards
(123 cards)
1
Q
changes in synaptic transmissionn is known as
A
synaptic plasticity
2
Q
what is synaptic plasticity
A
changes in synaptic transmission
3
Q
synaptic plasticity is a change in how well a ______ cell can fire
A
pre synaptic cell
4
Q
synaptic plasticity is the basis for ____ and _____
A
learning and memory
5
Q
synaptic plasticity can result from changes in
A
- the amount of neurotransmitter released
- the amount of receptor present
- gene expression that affect these mechanisms
- gene expression that affect the growth of new synapses
6
Q
t/f plastic changes only occur for a few seconds
A
false, plastic changes can be over in miliseconds or over a lifetime
7
Q
when measuring setup for measuring plasticity does the stimulating electrode go into the presynaptic or post synaptic neuron
A
presynaptic
8
Q
when measuring plasticity does the recording electrode go into the pre or post synaptic electrode
A
post synaptic
9
Q
if a presynaptic neuron is stimulated what will occur
A
if a presynaptic neuron is stimulated it will cause a psp in the post synaptic cell
10
Q
what does the amplitude of psp tell you
A
it tells you how good the presynaptic neuron is at making the post synaptic neuron fire
11
Q
what are the 3 steps to measuring synaptic plasticity
A
- measure the psp at baseline
- induce plasticity by giving a high frequency stimulus (tentanus)
- go back to baseline
12
Q
what is tentanus
A
the delivery of a brief high frequency stimulus
13
Q
an incident of high frequency can change the _____of a cell
A
plasticity
14
Q
usually the magnitue of a psp is plotted relative to what
A
the baseline
15
Q
when recording plasticity what are we measuring
A
we are measuring the synapse
16
Q
the day your child was born or ptsd is an example of
A
high frequency stimulation
17
Q
t/f high frequency is usually tied to negative events
A
false it can occur from negative or positive events
18
Q
define short term plasticity
A
occur and maintains itself for at most a few minutes
19
Q
how does short term plasticity occur
A
it results from repeated stiumulation of the same synapse
20
Q
t/f long term synaptic plasticity can last for a few years
A
true
21
Q
t/f all plasticity begins with immediate short term change
A
true
22
Q
what are the 2 types of long term synaptic plasticity
A
2 : long term potentiation and long term depression
23
Q
what does LTP mean
A
long term potentiation
24
Q
what does LTD mean
A
long term depression
25
define LTP
an increase in the size of the EPSP that is sustained for at least several minutes . it strengthens the synapse since it makes the presynaptic more likely to fire
26
does LTP make a pre synaptic cell more or less likely to fire
more likely
27
how long does LTP last
for months or years
28
define LTD
a decrease in the size of the EPSP that is sustained for at least several minutes
29
does LTP or LTD weaken the synapse
LTD
30
During LTD is a cell more or less likely to fire
less
31
how long can LTD last
for months to years
32
what determines if you will have LTD or LTP
The pattern of presynaptic stimulation determines whether there will be long term plasticity and of what type
33
if there is a slow pattern of presynaptic stimulation (1 hz) will you have LTP or LTD
LTD
34
If there is a fast pattern of presynaptic stimulation (100 hz ) will you have LTD or LTP
LTP
35
T/F All neurons have the same ability to show LTP or LTD
False, different types of neurons differ in their ability to show LTP or LTD
36
t/f if you want study LTP and LTD you must choose the right area of the brain
true
37
name one site of LTP and LTD
The hippocampus
38
name the area of the brain that is involved in the formation and retrieval of episodic memory
hippocampus
39
what is episodic memory
memory of autobiographical events
40
what is the name of the main input site in the hippocampal circuit
perforant path
41
if there is damage to the hippocampus what will likely occur
what you already will not be affected, but you will not be able to make new memories
42
describe the 1st synapse in the hippocampal circuit (trisynaptic circuit)
synapse with the granule cells of the dentate gyrus
43
what is the name of the axons on granule cells
mossy fibers
44
what kind of cells are located in the ca3 region
pyramidal cells
45
where do mossy fibers extend to
the ca3 region
46
pyramidal cells in the ca3 regionn send axons to what region
ca1 region aka schaffer collaterals
47
schaffer collateral links what 2 regions
ca3 - ca1
48
if you wanted to investigate LTP what would you stimulate
shaffer collaterals in 2 places to have both a test and a control pathway
49
if you delivered a High frequency stimulation to pathway 1 and not to pathway 2 what would you observe
in pathway 1 the frequency would remain higher after the stimulation . in pathway 2 there would be no change in the synapse
50
what does HFS induce
LTP
51
high frequency stimulation induces a long lasting increase in what
synaptic transmission
52
define specificity
when something is synapse specific
53
the hippocampus is what we call the _______ circuit
trisynaptic
54
what kind of cells are in the ca3 region
glutamatergic excitatory pyramidal cells
55
what kind of cells are in the ca1 region
glutamatergic excitatory pyramidal cells
56
information is sent out of the hippocampus via what
the sabicculum
57
when a recording is done in vivo what does that mean
on a live animal
58
t/f hippocampal LTP can only last for a few months
false , it can last for years
59
HFS simulates the ______ cell firing at a high rate
presynaptic cell
60
why does HFS cause LTP
more neurotransmitters are released so receptors have to respond so the cells knows that it is important so they will strenghthen the synapse
61
what is hebbs law
neurons that fire together , wire together
62
this is an example of what law? when an axon of cell A is near enough to cell B and repeatedly or persistently takes part in firing it , some growth process or metabolic change takes place in one or both cells such that A's efficiency as one of the cells firing B is increased
hebbs law
63
a strong stimulation at one synapse strengthens transmission at a weak synapse , this is an example of what
associative concept
64
if there is a high frequency stimulation at pathway 1 and inactivity at pathway 2 what will occur
synapse 2 will never strengthen
65
if there is strong stimulation at pathway 1 and weak stimulation at pathway 2 what will occur
because both are occuring at the same time , it will strengthen
66
high frequency stimulation induces what where
hfs induces ltp at the hippocampal schaffer collateral ca1 synapse
67
t/f LTP is not hebbian in nature
false
68
t/f weak synapses coincident with strong synapses will not demonstrate LTP
false
69
what is released at the presynaptic terminal
glutamate
70
what are the 2 kinds of receptors at the post synaptic terminal
AMPA and NMDA receptors
71
when the pre synaptic cell releases glutamate is it depolarized or hyperpolarized
depolarized
72
what are spines
excitatory synapses that are small protrusions
73
where are spines found
they are excitatory synapses on hippocampal and cortical dendrites are often on small protrusions called spines
74
if someone has fewer spines what can occur
mental retardation
75
are AMPAR and NMDAR's found on the pre or post synaptic cell
post synaptic
76
if transmission rates are low and the post synaptic membrane is at rest what kind of receptors are open
AMPAR
77
T/F at low transmission rates only NMDAR are open
false , only AMPAR are open
78
if transmission rates are high which receptors are open
AMPAR and NMDAR
79
when transmission rates are high is the post synaptic membrane hyperpolarized or depolarized
depolarized
80
when NMDAR open a series of events occur which ultimately ends with ..
the insertion of more AMPAR into the membrane
81
what physically strengthens a synapse
the insertion of new AMPAR
82
what is the role of the NMDAR
without it more ampa receptors can not be inserted , essentially you can not learn
83
t/f without NMDAR you can not have LTP
true
84
what 2 things have to open in order for NMDAR's to open
post synaptic depolarization and glutamate
85
t/f AMPAR's are known as coincidence detectors
false , NMDARs are
86
what kind of receptor is known as a coincidence detector ?
NMDARs
87
what ion calcium comes in when NMDAR's open ?
calcium comes into the terminal
88
what ion is crucial for LTP
calcium
89
what is the role of calcium chlelators
they block LTP
90
What does the injection of calcium do to a cell
it potentiates transmission
91
influx of calcium activates what 2 things
activation of 2 kinases : alpha camkinase and protein kinase
92
what is the name of the most abundant postsynaptic protein at the schaffer collateral synapse
CAmkii
93
where are the only 2 places that camKii is released
the cortex and hippocampus
94
if there is no caMkII is LTP possible
no
95
camKii are able to stimulate their own activity via
autophosphorlation
96
persistence of CamKII activity is due to what
autophosphorlationn
97
what allows for the insertion of more AMPARs
alpha cam kinase and protein kinase
98
during hippocampal LTP what receptors open first
NMDAR's open first
99
what ion rushes in after NMDARs open during hippocampal LTP
calcium
100
More AMPARs = more ____
potentiation
101
the increase of LTP is more synaptic strength or less synaptic strength?
more synaptic strength
102
does schaffer collateral have a pre or post synaptic locus of plasticity
postsynaptic
103
when there is ampar insertion does this result in an increase in LTP or LTD
LTP
104
When LTP increases , this results in an increase in amplitude of _______
EPSP
105
what is L-LTP
Late LTP
106
If you apply protein synthesis blockers what occurs to to LTP.
you get LTP but it decays after several hours
107
L-LTP depends on what 2 things
gene transcription and protein synthesis
108
L-LTP leads to the growth of new ____
spines
109
t/f cells can potentiate all the time
false
110
the flip side of long term potentiation is known at
LTD
111
You get LTD at the schaffer collateral synapse by using what ?
prolonged low frequency stimulation - 1 hz
112
is LTD associated with the gain or loss of AMPARs
loss
113
instead of kinases , LTD relies on what
calcium dependent phosphatases
114
are phosphotase inhibitors affected by LTP
No, only LTD
115
whether you get LTP or LTD depends on what
the amount of calcium influx
116
if there is a large and fast influx of calcium will LTP OR LTD RESULT?
LTP
117
If there is a small and slow influx of calcium will LTD or LTP occur
LTD
118
During LTD are AMPARs created or taken away
they are taken away
119
name a site of LTD
cerebellum
120
this part of the brain is involved in motor control and responsible for several types of motor learning
cerebellum
121
where does LTD occur in cerebellum
at the parallel fiber purkinje cell synapse
122
LTD at the cerebellar LTD only occurs when what 2 fibers are activated at the same time
climbing fibers and parallel fibers
123
during LTD what happens at the climbing fiber synapse
climbing fiber input depolarizes the dendritic membrane.
