Lecture 7 Flashcards

1
Q

T or F? Exc or Inh inputs can be received in a dendrite.

A

T

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2
Q

Why is the AP threshold lowest at the trigger zone?

A

more Na channels

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3
Q

T or F? Exc or ing inputs decrease in time.

A

T

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4
Q

T or F? The threshold for each cell is constant for all surfaces of the cell.

A

F. Lower threshold at the trigger zone (more Na channels)

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5
Q

What determines relative efficacy of input to create an AP?

A

proximity to synapse

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6
Q

T or F? A distal synapses with the same level of exc input will have a greater impact than one that is more proximal.

A

F. vice versa

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7
Q

How are synaptic potentials integrated?

A

spatially and temporally

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8
Q

These are the dominant player after threshold is reached?

A

Voltage gated Na channels

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9
Q

EPSP’s are used in reference to __ and EPP’s are used in reference to:

A

CNS, NMJ

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10
Q

EPSP’s are triggered by ___ and EPPs are triggered by:

A

glutamate, AcH (and glutamate)

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11
Q

Why can synaptic pot’s increase temporal?

A

build up of Ca bc they don’t have time to close completely

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12
Q

The buildup of _____ leads to temporal summation of synaptic potentials:

A

Ca

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13
Q

There ___ times more Ca outside the cell than inside.

A

10,000

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14
Q

Why will low freq stimulation generate the same size EPSP?

A

Ca had time to return to baseline

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15
Q

T or F? Spatial and temp can only happen with EPSP .

A

F. Both EPSP and IPSP

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16
Q

Can inhibition be presyn, postsyn, or either.

A

either

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17
Q

Postsynaptic inhibition is mediated by:

A

GABA(aR)

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18
Q

What molecule is used in postsynaptic inhibition?

A

Cl- (GABA is a chloride channel)

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19
Q

What affect postsyn inhibition have on an EPSC?

A

shunt and reduce the efficacy

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20
Q

Where are postsyn inhibitory synapses located?

A

dendritic shaft of cell body near AP trigger zone

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21
Q

T or F? Inhibitory synapses can only work locally.

A

T

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22
Q

T or F? Inhibitory synapses can decrease the efficacy of excitatory inputs over the whole cell globally.

A

T

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23
Q

Where does presynaptic inhibition usually occurs?

A

at axon-axonic synapse

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24
Q

What does it mean if you decrease the efficacy of an EPSP?

A

size decreases

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25
Q

What type of channel does presynaptic inhibition target?

A

Ca channels

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26
Q

What type of receptor is involved with presynaptic inhibition?

A

GABA(b)

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27
Q

What type of receptor is GABA(b)?

A

metabotropic receptor

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28
Q

What affect will GABA(b) receptor have on ion levels?

A

decrease Ca channels

29
Q

T or F? Presynaptic inhibition increases the amount of T release.

A

F. Decreases

30
Q

Another term for amount of T released:

A

quantal content

31
Q

In which pathways does presynaptic inhibition play a prominent role?

A

sensory system pathways

32
Q

presynaptic inhibition plays this role in sensory system pathways:

A

habituation

33
Q

Define habituation:

A

filter out non-meaningful info (noise, monotonic tones in auditory pathway)

34
Q

Principle T of presynaptic inhibition:

A

GABA

35
Q

These neurotransmitters regulate diverse populations of neurons:

A

neuromodulators

36
Q

Each T has only one specific type of receptor.

A

F. Can have diff receptors

37
Q

T or F? The presynaptic, inhibitory metabortropic GABA receptor is voltage dependent.

A

T

38
Q

Presynaptic uses GABA__ and postsynaptic uses GABA___.

A

b, a

39
Q

To where do inhibitory interneurons attach?

A

to the sensory afferent that is attached to the neuron of interest

40
Q

T or F? Inhibitory interneurons can only be effective if they are stimulated after the sensory afferent.

A

F. must be stimulated before

41
Q

Inhibitory interneurons inhibit the initial synapse by releasing:

A

GABA

42
Q

The release of GABA by the interneuron has what affect?

A

this inhibits the release of glutamate, leading to a smaller EPSP

43
Q

How does GABA(b) affect the channels of the sensory afferent neuron?

A

deactivation of Ca channels and activation of Ka channels

44
Q

T or F? GABA(b)R’s increase the rate of cell depolarization.

A

F. increase the rate of repolarization

45
Q

What affect will GABA(b)R’s have on T release?

A

decrease it

46
Q

monosynaptic pathway is exc/ inh?

A

exc

47
Q

Bisynaptic pathway is exc/inh?

A

inh

48
Q

The Renshaw cell is mediated by:

A

‘slow’ and ‘fast’ postsynaptic transmission

49
Q

Affect of RC on weakly excited MN in motor center:

A

inhibits

50
Q

Affect of RC on strongly excited MN in motor center:

A

decreases firing rate (fine tunes muscle control)

51
Q

This is involved in fine tune muscle control:

A

Renshaw cell

52
Q

T or F? Inhibitiory interneuron are glycinergic and induces EPSP’s.

A

F. 1st part true, but induce IPSP’s

53
Q

This can lead to prolonged m. contraction:

A

No feedback control

54
Q

Too much AcH released will activate (this type of) receptors through ________ that will either release AcH (cholinergic) to activate nicotinic receptors at NMJ or release AcH to activate muscarinic at the interneuron (Renshaw cell)

A

muscarinic, axon collaterals

55
Q

What kind of receptors are at the NMJ?

A

nicotinic (AcH)

56
Q

What type of receptor are at the interneuronal junction?

A

muscaarinic

57
Q

T or F? Muscarinic is ionotropic.

A

F.

58
Q

What affect will muscarinic receptors have on interneurons?

A

decrease K channels and increase the firing

59
Q

acetylcholine receptors that form G protein-receptor complexes:

A

muscarinic AcH receptors

60
Q

T or F? nAChRs and mAChRs are both used in the ANS.

A

T

61
Q

What affect will mAChR have on the RC cell?

A

stimulatory increase

62
Q

The exc RC cell will release this once excited

A

glycine (feedback mechanism)

63
Q

Excitation of interneuron leads to:

A

inhibition

64
Q

Fast synaptic transmission will always activate:

A

the intrinsic ion channels

65
Q

Fast synaptic transmission can be exc, inh, or either?

A

either

66
Q

___ is involed in the fast pathway and ___ is involved in the slow pathway.

A

gly, AcH

67
Q

Branch off of a neuron that projects back to the neuron itself:

A

axon collateral

68
Q

What is the relationship between capacitance and resistance?

A

inversely related (check)