Exam 3 Practice Questions

Question 1

In the central nervous system, which cells myelinate axons?
a. Microglia
b. Schwanncells
c. Oligodendrocytes
d. Astrocytes

Answer 1

C. Oligodendrocytes

Question 2

In the peripheral nervous system, which cells myelinate axons?
a. Microglia
b. Schwann cells
c. Oligodendrocytes
d. Astrocytes

Answer 2

B. Schwann cells

Question 3

Central nervous system axons
a. Regenerate better than peripheral axons
b. Regenerate more poorly than peripheral axons
c. Regenerate quicker than peripheral axons
d. Regenerate in the opposite direction of the lesion

Answer 3

b. Regenerate more poorly than peripheral axons

Question 4

What is a likely source of signals preventing central axon regeneration?
a. Schwann cells
b. Oligodendrocytes
c. Osteoblasts
d.Stem cells

Answer 4

b. Oligodendrocytes

Question 5

Comparisons of what types of cells led to the discovery of several types of signals preventing regeneration
a. Osteoblasts and osteoclasts
b. Astrocytes and osteoblasts
c. Oligodendrocytes and Schwann cells
d.Schwann cells and stem cells

Answer 5

c. Oligodendrocytes and Schwann cells

Question 6

Which hippocampal pathway exhibits a presynaptic mechanism of LTP?
a. Schaffer collateral
b. Commissural pathway
c. Mossy fiber pathway
d. Direct perforant pathway

Answer 6

c. Mossy fiber pathway

Question 7

Mossy fiber LTP requires activation of which
a. NMDA receptors
b. L-type calcium channels
c.PKA
d.CamKII

Answer 7

C. PKA

Question 8

Mossy fiber LTP can be induced by
a.Carefully timing presynaptic spikes with postsynaptic spikes
b.Tetanic presynaptic stimulation
c.It can’t be induced
d. All of the above

Answer 8

b. Tetanic presynaptic stimulation

Question 9

Which of the following enzymes is activated in the post-synaptic cell when the facilitating interneuron activates it? (regraded; idk the answer)
a. PKG
b. FYN
c. PKA
d. Calmodulin

Answer 9

c. PKA

Question 10

LTP in the Schaffer collateral and the direct perforant pathway differs in the presence of which of the following mechanisms?
a. NMDA receptors
b. Shaker potassium channels
c. L-type calcium channels
d. Calmodulin

Answer 10

c. L-type calcium channels

Question 11

Which of the following hippocampal pathways are associative
a. Commissural pathway
b. Direct perforant pathway
c. Schaffer collateral
d. All of these

Answer 11

c. Schaffer collateral

Question 12

In the presynaptic mechanism of hippocampal LTP, which is the coincidence detector?
a. NMDA receptors
b. There is no coincidence detector
c. Adenylyl cyclase
d. Calmodulin

Answer 12

b. There is no coincidence detector

Question 13

In a synapse that can engage in postsynaptic LTP, what is the most likely cause of LTD instead of LTP?
a. NMDA activation
b. AMPA activation
c. Long slow calcium current
d. Rapid calcium current

Answer 13

c.Long slow calcium current

Question 14

What is the main difference between early vs late phase LTP
a. CaMKII activation
b. Gene expression
c. Calcineurin activation
d. Calmodulin activation

Answer 14

b. gene expression

Question 15

Which of the following mechanisms is involved in increasing the sensitivity of a synapse expressing the postsynaptic mechanism of LTP
a. NMDA dephosphorylation
b. L-type calcium channel phosphorylation
c. AMPA phosphorylation
d. Potassium channel phosphorylation

Answer 15

b. L-type calcium channel phosphorylation

Question 16

In a synapse that can engage in postsynaptic LTP, what is the most likely cause of LTD instead of LTP?
a. Calmodulin activation
b. Rapid large calcium current
c. Calcineurin activation
d. AMPA activation

Answer 16

c. Calcineurin activation

Question 17

Which hippocampal pathway has a presynaptic mechanism of LTP?
a. Commissural
b. Schaffer collateral
c. Mossy fibers
d. Direct perforant

Answer 17

C. Mossy fibers

Question 18

In the presynaptic mechanism of hippocampal LTP, how do we know it is presynaptic?
a. Blocking calcium channels blocks the effect
b. Blocking PKA has no effect
c. Blocking PKA blocks the effect
d. Blocking NMDA receptors blocks

Answer 18

a. Blocking calcium channels blocks the effect

Question 19

Which of the following mechanisms is involved in increasing the sensitivity of a synapse expressing the postsynaptic mechanism of LTP?
a. Phosphorylation of L-type calcium channels
b. Calcineurin activation
c. Insertion of new AMPA receptors
d. Insertion of new NMDA receptors

Answer 19

c. Insertion of new AMPA receptors

Question 20

Spike timing-dependent plasticity, where cell A is presynaptic cell B, which of the following scenarios would result in strong LTD?
a. Cell B intermittently fires long before cell A
b. Cell B consistently fires immediately before cell A
c. Cell A consistently fires immediately before cell B
d. Cell A intermittently fires long before cell

Answer 20

a. Cell B intermittently fires long before cell A

Question 21

Regarding spike-timing-dependent plasticity, where cell A is presynaptic to cell B, which of the following scenarios would result in strong LTP?
a. Cell A consistently fires immediately before cell B
b. Cell B consistently fires immediately before cell A
c. Cell B intermittently fires long before cell A
d. Cell A intermittently fires long before cell B

Answer 21

a. Cell A consistently fires immediately before cell B

Question 22

31. During hippocampal LTP, increased EPSPs can result from:
    a. Insertion of vesicles carrying AMPA receptors into the plasma membrane
    b. Dephosphorylation of membrane AMPARS
    c. Phosphorylation of membrane AMPARS
    d. Activation of protein phosphatases
    e. A and C
    f. C and D

Answer 22

e. A and C

Question 23

The late phase of LTP requires the activation of additional molecular processes in the postsynaptic neuron compared to the early phase. One example of that additional mechanism is:
a. Activation of protein phosphatases
b. Activation of protein kinases
c. Insertion of additional AMPARS into the postsynaptic membrane
d. Protein synthesis de novo (synthesis of new proteins) and gene expression
e. Internalization of membrane NMDARS (pulling NMDARS from the membrane into the cytosol)

Answer 23

d. Protein synthesis de novo (synthesis of new proteins) and gene expression

Question 24

NMDARS and AMPARS are
a. Ligand-gated receptors
b. Neurotransmitter-gated ion channels
c. Ionotropic receptors
d. Cation-permeable channels
e. All of the above
f. None of the above

Answer 24

e. all of the above

Question 25

Both AMPA and NMDA receptor types require postsynaptic membrane depolarization as well as ligand binding to open a. True b. False

Answer 25

a. True

Question 26

What do you know about AMPA receptor phosphorylation in the postsynapse during LTP? a. It leads to an increase in subsequent EPSPS b. It is mediated by protein phosphatases c. It leads to less active AMPARS d. It requires very small calcium increases

Answer 26

a. It leads to an increase in subsequent EPSPS

Question 27

The induction of LTP at a given synapse is independent of the activity of the presynaptic cell a. True b. False

Answer 27

b. False

Question 28

LTP and LTD are types of plasticity neuronal networks used to encode relevant (important) vs nonrelevant information a. True b. False

Answer 28

a. True

Question 29

The reason why NMDARS do not open simply because their ligand is bound to them is because the receptor channel’s pore is occupied by a manganese ion, which needs to be expelled by membrane depolarization a. True b. False

Answer 29

a. True

Question 30

Behavioral sensitization, mediated by synaptic facilitation of the gill withdrawal reflex in Aplysia is mediation by connections between the ________ interneuron from the tail and the sensory neurons innervating the terminal of the ________ and the mantle.

Answer 30

Behavioral sensitization, mediated by synaptic facilitation of the gill withdrawal reflex in Aplysia is mediation by connections between the **facilitated** interneuron from the tail and the sensory neurons innervating the terminal of the **siphon** and the mantle.

Question 31

This interneuron from the tail releases ________ on the pre-synaptic terminal of the ____ and the siphon mantle.

Answer 31

This interneuron from the tail releases **5HT** on the pre-synaptic terminal of the **Siphon** and the siphon mantle.

Question 32

This neurotransmitter then activates two separate receptors, the first Gq/11 protein-coupled receptor activates ________, which is a membrane-bound protein that diffuses through the membrane and cleaves ____ into inositol triphosphate and DAG

Answer 32

This neurotransmitter then activates two separate receptors, the first Gq/11 protein-coupled receptor activates **PKC**, which is a membrane-bound protein that diffuses through the membrane and cleaves **PIP2** into inositol triphosphate and DAG

Question 33

____________ then translocate to the membrane where it first interacts with phosphatidyl serine and then _________ which removes the pseudosubstrate from the catalytic cavity

Answer 33

**PKA** then translocate to the membrane where it first interacts with phosphatidyl serine and then **ligands** which removes the pseudosubstrate from the catalytic cavity

Question 34

This enzyme then diffuses through the membrane and interacts with its catalytic targets namely voltage-gated ________ channels and the neurotransmitter release and vesicle recruitment machinery

Answer 34

This enzyme then diffuses through the membrane and interacts with its catalytic targets namely voltage-gated **Ca2+** channels and the neurotransmitter release and vesicle recruitment machinery

Question 35

The other g protein-coupled receptor, the ____protein-coupled receptor activates ____ which converts ATP to ____ binds the inhibitory subunits, and releases the catalytic subunits of the enzyme_____

Answer 35

The other g protein-coupled receptor, the **Gs** protein-coupled receptor activates **adenyl cyclase ** which converts ATP to **cAMP** binds the inhibitory subunits, and releases the catalytic subunits of the enzyme **PKA**

Question 36

This kinase phosphorylates voltage-gated __________ ion channels, voltage-gated ________ ion channels, and the neurotransmitter release and vesicle recruitment machinery, enhancing the release of NT into the synapse

Answer 36

This kinase phosphorylates voltage-gated **Ca2+** ion channels, voltage-gated **K+** ion channels, and the neurotransmitter release and vesicle recruitment machinery, enhancing the release of NT into the synapse

Question 37

What type of pre-synaptic stimulation will cause LTD instead of LTP?

Answer 37

Post before pre

Question 38

What differs in the mechanism to induce LTD instead of LTP (think Calcium and how it activates what)?

Answer 38

Small increases in Ca2+

Question 39

What type of presynaptic stimulation will cause LTD instead of LTP?

Answer 39

Low-frequency stimulation ( or pre-synaptic firing) leads to depression in the post-synaptic cell. EPSP is going to be lower than the baseline EPSP

Question 40

# Characterize STDP with Hebbian or Anti-Hebbian with bias

Answer 40

* Even curve in quadrance 2 and quadrant 3 --> hebbian (classic, not biased) * Curve with a bump on top in quadrant 2, smaller curve in quadrant 3 --> Hebbian (LTP-biased) * Only valley below the x-axis in quadrants 3 and 4 --> anti-hebbian (LTD only)

Question 41

# For each question answer with large or small LTP or LTD a. Regarding Figure A what type of LTP will result with a large positive delta t? b. Regarding Figure B what type of plasticity will result from a small negative delta t? c. Regarding Figure C what type of plasticity will result from a small positive LTP? ## Footnote disregard red numbers

Answer 41

a. small LTP because of no changein plasticity and there is no indication of coincidence so nothing will change b. small LTD c. large LTD

Question 42

In a sentence describe how NMDA receptors are activated and what type of current results

Answer 42

In LTP NMSA activation comes from depolarization in glutamate and a large influx of calcium renders LTP current

Question 43

Describe the difference between sensitization and classical conditioning. Your answer should be very specific and include ( but not be limited to) differences in the experimental paradigm, behavioral response, as well as cellular and molecular differences in the process. The sensitization paradigm includes one poking the siphon, shocking the tail, and then poking the siphon again. The result of this paradigm is that the gill then withdraws for all types of stimulus, including harmless stimuli in a more exaggerated manner.

Answer 43

* Classical conditioning involves pre-synaptic and post-synaptic coordination. * Timing is crucial in conditioning. * Tail shock occurs immediately after touching the siphon. * Pairing conditioned and unconditioned stimuli results in sensitization and habituation. * Both mechanisms are pre-synaptic, with sensory neurons playing a key role. Sensitization and Classical Conditioning Mechanisms Sensitization: * Facilitated interneuron releases serotonin onto sensory neuron, binds to Gs and Gq/11 pathways, activates PKA & PKC, and increases NT release and EPSP. * Broadened Action Potential (AP) in Gs pathway due to PKA activation by cAMP from adenylyl cyclase. * Broadened AP allows more CA2+ to enter the cell, enhancing vesicle recruitment. * PKC phosphorylates L-type ca2+ channels, increasing vesicle recruitment and docking average number of vesicles. Classical Conditioning: * Sensory neuron action potential precedes shock for calmodulin to be activated, activating facilitated interneuron and serotonin release. * Calmodulin, associated with Adenylyl cyclase, enhances Action potential and bigger PKA activation. * Action potential in sensory neuron causes more CA2+ to enter the cell, leading to Calmodulin activation and Adenyly cyclase 4 primed, enhancing AP and bigger PKA. * MAP K inhibits CREB 2 and activates CREB 1, directing gene transcription and PKA activation. | answer broken up on other slides as well

Question 44

Describe Classical Conditioning

Answer 44

Classical Conditioning: * Sensory neuron action potential precedes shock for calmodulin to be activated, activating facilitated interneuron and serotonin release. * Calmodulin, associated with Adenylyl cyclase, enhances Action potential and bigger PKA activation. * Action potential in sensory neuron causes more CA2+ to enter the cell, leading to Calmodulin activation and Adenyly cyclase 4 primed, enhancing AP and bigger PKA. * MAP K inhibits CREB 2 and activates CREB 1, directing gene transcription and PKA activation.

Question 45

Describe Sensitization

Answer 45

Sensitization: * Facilitated interneuron releases serotonin onto sensory neuron, binds to Gs and Gq/11 pathways, activates PKA & PKC, and increases NT release and EPSP. * Broadened Action Potential (AP) in Gs pathway due to PKA activation by cAMP from adenylyl cyclase. * Broadened AP allows more CA2+ to enter the cell, enhancing vesicle recruitment. * PKC phosphorylates L-type ca2+ channels, increasing vesicle recruitment and docking average number of vesicles.

Question 46

What is the source of inhibitory signals in central axon regeneration, and how do we know?

Answer 46

The source of inhibitory signals in central axon regeneration is the CNS myelin. We know this from past studies that were done with rats where if you block myelin sensory fibers extend normally and sprout new collaterals following denervation in myelin-free spinal cords. But if you don't block the central axons of the branch are degenerated leaving a portion of the denervated, so little re- generation occurs in the myelin-rich cord.

Question 47

Describe the basic concept behind the synaptic tagging hypothesis.

Answer 47

The basic concept of synaptic tagging is synaptic activity "tags" a specific synapse, which essentially primes it for plasticity-induced changes. The specific tag is still unknown but multiple kinases, ion channels, and adhesion molecules have been implicated.

Question 48

Briefly explain the difference between E-LTP and L-LTP. What are the cellular events that differentiate them?

Answer 48

E- LTP is what makes the synapse more sensitive to short- term changes, the same stimulation leads to a larger response (EPSP) - PKC phosphorylates AMPA receptors, causing the insertion of AMPA receptors, then CAM K 2 phosphorylates AMPA receptors in the membrane and sensitizes them. Result in a more robust EPSP for the same amount of stimulation. L-LTP activation of gene transcription, longer-term changes- Cam K 4 w/ MAPK phosphorylates CREB, and activation of gene transcription from early phase to late phase

Question 49

NMDA-dependent LTP and LTD can be caused by differential levels of the same type of presynaptic (non-associative) stimulation. What type of presynaptic stimulation will cause LTD instead of LTP and what differs in the mechanism to induce LTD instead of LTP (think calcium and how it activates what)?

Answer 49

Long-Term Potentiation and Long-Term Depression in NMDA Receptor-Dependent Neurons * Low-frequency stimulation (LFS) of presynaptic neurons, typically 1-5 Hz, is more likely to induce LTD. * High-frequency stimulation (HFS), typically around 100 Hz, is more likely to induce LTP. * LTD induction occurs when LFS results in a moderate increase in postsynaptic calcium, activating protein phosphatases and reducing the strength of the synapse. * LTP induction occurs when high-frequency stimulation leads to a larger calcium influx, activating calcium/calmodulin-dependent protein kinases (CaMKs), enhancing synaptic strength and promoting LTP. * In summary, low-frequency stimulation induces LTD, while high-frequency stimulation strengthens synapses and induces LTP.

Question 50

Describe the prototypical process of NMDA-dependent LTP. Be sure to include short-term and long-term mechanisms mediating this phenomenon

Answer 50

NMDA dependent LTP, NMDA receptor is glutamatergic and ionotropic, ion channel means it allows cations to flow through, allows Ca2+ to go through along with Na and K, also Mg is associated with pore as negative charge to block the pore, Mg needs additional force to be ejected

Question 51

Identify the role of myelin in the regeneration of central neurons

Answer 51

Myelin forming oligodendrocytes have little or no ability to dispose of myelin, and the blood-brain barrier prevents the entry of macrophages, so removal of debris depends on a limited quantity of resident macrophages and microglia. One is that postsynaptic injury causes axon terminals to lose their adhesiveness to synaptic sites so that they are subsequently wrapped by glia. The other is that glia initiate the process of synaptic stripping in response to factors released from the injured neuron or to changes in its cell surface.

Question 52

What is the source of inhibitory signals in central axon regeneration, and how do we know?

Answer 52

Myelin-Associated Inhibitors and Extracellular Matrix Components in the Glial Scar Myelin-Associated Inhibitors: * In vitro experiments show limited axon outgrowth in cultured neurons plated on myelin or myelin-derived proteins. * Specific inhibitors like Nogo, myelin-associated glycoprotein (MAG), and oligodendrocyte-myelin glycoprotein (OMgp) were identified. * Antibodies or receptor blockers against these inhibitors promoted axon regeneration in animal models of spinal cord injury or optic nerve crush. Extracellular Matrix Components in the Glial Scar: * The glial scar contains reactive astrocytes, microglia, and a dense extracellular matrix rich in chondroitin sulfate proteoglycans (CSPGs). * CSPGs, produced by reactive astrocytes, inhibit axon growth and regeneration. * Treatment with chondroitinase ABC or blocking specific CSPG receptors on neurons enhanced axon regeneration

Question 53

Briefly explain the difference between E-LTP and L-LTP. What are the cellular events that differentiate them

Answer 53

Early long-term potentiation (E-LTP) is the first step of long-term potentiation (LTP). We can study the form of synaptic plasticity, and it is responsible for increase in synaptic strength. L- Long-term potentiation (LTP) is known for continuous increase in strength of synapse by stimulating the high-frequency of chemical synapse. We can study the LTP By carrying out the hippocampus, Cellular changes are : LTP originates when we stimulate a single synapse repeatedly . This event result in stimulation that causes a calcium- and CaMKII-dependent cellular cascade, which results in the insertion of more AMPA receptors which is present in synapses

Question 54

Describe the presynaptic mechanism that underlies mossy fiber LTP

Answer 54

* LTP is a synaptic plasticity at synapses between mossy fibers and CA3 pyramidal neurons. It increases the probability of neurotransmitter release from mossy fibers' presynaptic terminals. This increase is triggered by presynaptic calcium levels, activated by high-frequency stimulation. Elevated calcium levels activate signaling pathways, including CaMKII and MAPK pathways. These pathways phosphorylate and modulate presynaptic proteins involved in neurotransmitter release, facilitating synaptic vesicle mobilization and priming. Structural changes in presynaptic terminals increase the number of docked vesicles and expand the active zone area, enhancing neurotransmitter release probability.

Question 55

Describe the process of NMDA-dependent LTP. Be sure to include both short and long-term mechanisms mediating this phenomenon.

Answer 55

NMDA Receptor-Dependent Long-Term Potentiation Process Short-Term Mechanisms: High-frequency stimulation of presynaptic neurons initiates NMDA receptor-dependent LTP. Depolarization of the postsynaptic membrane releases Mg2+ block from NMDA receptors Ca2+ enters postsynaptic neurons, activating calcium/calmodulin-dependent protein kinase II (CaMKII). CaMKII phosphorylates AMPA receptors, increasing conductance and short-term synaptic response potentiation. Long-Term Mechanisms: * The inflow of Ca2+ activates the Ras/MAPK pathway and CaMK kinase/CaMKIV pathway, activating transcription factors like CREB. * These transcription factors initiate the transcription of immediate early genes, leading to protein synthesis for long-term LTP maintenance. * New proteins regulate synaptic structure and function, creating a self-perpetuating cycle of gene expression and synaptic modifications. * These changes at the synapse underlie long-term maintenance of NMDA receptor-dependent LTP, a cellular mechanism for learning and memory formation.

Question 56

Describe the three types of LTP discussed in the hippocampus. What are they? What are the similarities and what are the differences?

Answer 56

Mossy Fiber LTP: * Located at synapses between mossy fibers and CA3 pyramidal neurons. * Primarily presynaptic, involving increased neurotransmitter release. * NMDA receptor-independent, relying on presynaptic kainate receptors and cAMP signaling pathways. Schaffer collateral LTP: * Located at synapses between Schaffer collaterals and CA1 pyramidal neurons. * Primarily postsynaptic, involving activation of NMDA receptors and synaptic strength increase. * NMDA receptor-dependent, requiring large postsynaptic calcium influx. Direct perforant path LTP: * Located at synapses between perforant path and dentate gyrus granule cells. * Shares similarities with both types, exhibiting both presynaptic and postsynaptic components. Similarities: * All three LTPs involve long-lasting synaptic strength increases and contribute to hippocampal plasticity and memory formation. * Share common signaling pathways, including calcium involvement and kinase activation. Differences: * Mossy fiber LTP is primarily presynaptic and NMDA receptor-independent. * Schaffer collateral LTP is postsynaptic and NMDA receptor-dependent. * Direct perforant path LTP combines presynaptic and postsynaptic components.

Question 57

Hebbian or Anti-hebbian, Biased and how?

Answer 57

Question 58

Hebbian or Anti-hebbian, Biased and how?

Answer 58

Question 59

Hebbian or Anti-hebbian, Biased and how?

Answer 59

Question 60

Hebbian or Anti-hebbian, Biased and how?

Answer 60

Question 61

In the peripheral nervous system, which cells myelinate axons? a. Microglia b. Schwann cells c. Oligodendrocytes d. Astrocytes

Answer 61

b. Schwann cells

Question 62

Damage to a CNS axon leads to progressive degeneration of the distal axon as well as a. Major downstream or postsynaptic connections b. Major presynaptic connections c. Myelin around the axon d. all of the above

Answer 62

d. all of the above

Question 63

Central nervous system axons a. Regenerate better than peripheral axons b. Regenerate more poorly than peripheral axons c. Regenerate quicker than peripheral axons d. Regenerate in the opposite direction of the lesion

Answer 63

b. Regenerate more poorly than peripheral axons

Question 64

Regarding the regeneration of a damaged axon, Schwann cells a. Prevent growth b. Impair growth c. Promote growth d. Eat babies

Answer 64

Promote Growth

Question 65

What is a likely source of signals preventing central axon regeneration? a. Schwann cells b. Oligodendrocytes c. Osteoblasts d. Stem cells

Answer 65

b. Oligodendrocytes

Question 66

Which is the prototypical mechanism of degradation that results from axon injury? a. Hebbian degeneration b. Wallerian degeneration c. Microglial degeneration d. Oligodegeneratoin

Answer 66

b. Wallerian degeneration

Question 67

What functions as the coincidence detector for classical conditioning in Aplysia? a. NMDA receptors b. AMPA receptors c. Adenyl Cyclase d. Phospholipase C

Answer 67

c. Adenyl Cyclase

Question 68

Sensitization requires modification of the sensory neuron synaptic terminal by which of the following? a. Sensory neuron b. Motor neuron c. Facilitating interneuron d. Mantle

Answer 68

c. Facilitating interneuron

Question 69

Activation of PKC by the Gq pathway requires a. Activation of Adenylyl Cyclase b. Activation of Phospholipase C c. Binding of glutamate d. Action potential broadening

Answer 69

b. Activation of Phospholipase C

Question 70

Which of the following is necessary to activate PKC in Aplysia during sensitization? a. Diacyl glycerol b. Phosphatidyl serine c. Phosphatidyl inositol biphosphate d. All of the above

Answer 70

d. all of above

Question 71

Mossy fiber LTP requires activation of which: a. NMDA receptors b. AMPA receptors c. PKA d. CamKII

Answer 71

c. PKA

Question 72

Mossy fiber LTP can be induced by a. Carefully timing presynaptic spikes with post-synaptic spikes b. Tetanic presynaptic stimulation c. It cant be induced d. All of the above

Answer 72

b. Tetanic presynaptic stimulation

Question 73

Which of the following cellular processes are hypothesized to be cellular correlates of memory a. LTP b. LTZ c. LTD d. Both a and c

Answer 73

d. Both a and c

Question 74

LTP is the Schaffer collateral and the direct perforant pathway differs in the presence of which of the following mechanisms? a. L-type calcium channel b. Shaker potassium channels c. Calmodulin d. NMDA receptors

Answer 74

a. L-type calcium channel

Question 75

Which of the following is a possible condition for the induction of NMDA-dependent LTP? a. High-frequency stimulation of presynaptic neurons b. Low-frequency stimulation of presynaptic neurons c. Activation of metabotropic glutamate receptors d. None of the above

Answer 75

a. High-frequency stimulation of presynaptic neurons

Question 76

Regarding spike-timing-dependent plasticity, where cell A is presynaptic to cell B, which of the following scenarios would result in strong LTD (long-term depression)? a. Cell B consistently firing immediately before cell A b. Cell A consistently firing immediately before cell B c. Cell B intermittently firing long before cell A d. Cell A intermittently firing long before cell B

Answer 76

a. Cell B consistently firing immediately before cell A

Question 77

Regarding the binomial distribution, what changes as a result of mossy fiber LTP? a. n b. p c. Q d. X e. None of the above

Answer 77

a. n

Question 78

Regarding the binomial distribution, what changes as a result of Schaffer Collateral LTP? a. n b. p c. Q d. X e. None of the above

Answer 78

e. None of the above

Question 79

Phosphorylation of AMPA receptors by PKC results in a. Insertion of new AMPA receptors into the membrane b. Removal of AMPA receptors from the membrane c. Insertion of NMDA receptors into the membrane d. Inactivation of NMDA receptors

Answer 79

a. Insertion of new AMPA receptors into the membrane

Question 80

The tracing shows an EPSP induced when cell A releases glutamate onto cell B. Which of the tracings to the left represents a likely change to the EPSP after LTD had occurred?

Answer 80

B

Question 81

At resting potential, in which direction will sodium flow if an ion channel specific to it is opened? a. Into the cell b. Out of the cell c. No net flow

Answer 81

a. into the cell

Question 82

At resting potential, in which direction will chloride flow if an ion channel specific to it is opened? a. Into the cell b. Out of cell c. No net flow

Answer 82

into the cell

Question 83

Which ion flows with its electrical gradient? a. Sodium b. Potassium c. Chloride d. None of these

Answer 83

a. Sodium

Question 84

Which ion flows against its concentration gradient? a. Sodium b. Potassium c. Calcium d. None of the above

Answer 84

d. none of the above | maybe b. Potassium

Question 85

For an average neuron, where can an action potential be initiated? a. Only at the axon hillock b. Only at the axon initial segment c. Only at the axon internodes d. Anywhere on the neuron

Answer 85

d. anywhere on the neuron

Question 86

# (Hebbian or antihebbian, and if there is a bias and what it is)

Answer 86

Hebbian LTP biased

Question 87

When studying the mechanism of hippocampal plasticity, what is commonly used for an induction protocol to ensure that LTP is induced?

Answer 87

Post tetanic potentiation

Question 88

Would the timing indicated by the III result in an increase or decrease in EPSC amplitude?

Answer 88

decrease in EPSP amplitude

Question 89

What is the frequency of this stimulation protocol?

Answer 89

10 HZ

Question 90

What is the delta t for this stimulation protocol?

Answer 90

25

Question 91

What does the z-axis represent?

Answer 91

Frequency of induction protocol

Question 92

Identify a frequency at which the synapse functions as a Hebbian

Answer 92

20 HZ

Question 93

Identify a frequency at which the synapse is LTD only

Answer 93

0.1 HZ