Lecture 7 Flashcards Preview

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Flashcards in Lecture 7 Deck (68):
1

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

T

2

Why is the AP threshold lowest at the trigger zone?

more Na channels

3

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

T

4

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

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

5

What determines relative efficacy of input to create an AP?

proximity to synapse

6

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

F. vice versa

7

How are synaptic potentials integrated?

spatially and temporally

8

These are the dominant player after threshold is reached?

Voltage gated Na channels

9

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

CNS, NMJ

10

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

glutamate, AcH (and glutamate)

11

Why can synaptic pot's increase temporal?

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

12

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

Ca

13

There ___ times more Ca outside the cell than inside.

10,000

14

Why will low freq stimulation generate the same size EPSP?

Ca had time to return to baseline

15

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

F. Both EPSP and IPSP

16

Can inhibition be presyn, postsyn, or either.

either

17

Postsynaptic inhibition is mediated by:

GABA(aR)

18

What molecule is used in postsynaptic inhibition?

Cl- (GABA is a chloride channel)

19

What affect postsyn inhibition have on an EPSC?

shunt and reduce the efficacy

20

Where are postsyn inhibitory synapses located?

dendritic shaft of cell body near AP trigger zone

21

T or F? Inhibitory synapses can only work locally.

T

22

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

T

23

Where does presynaptic inhibition usually occurs?

at axon-axonic synapse

24

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

size decreases

25

What type of channel does presynaptic inhibition target?

Ca channels

26

What type of receptor is involved with presynaptic inhibition?

GABA(b)

27

What type of receptor is GABA(b)?

metabotropic receptor

28

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

decrease Ca channels

29

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

F. Decreases

30

Another term for amount of T released:

quantal content

31

In which pathways does presynaptic inhibition play a prominent role?

sensory system pathways

32

presynaptic inhibition plays this role in sensory system pathways:

habituation

33

Define habituation:

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

34

Principle T of presynaptic inhibition:

GABA

35

These neurotransmitters regulate diverse populations of neurons:

neuromodulators

36

Each T has only one specific type of receptor.

F. Can have diff receptors

37

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

T

38

Presynaptic uses GABA__ and postsynaptic uses GABA___.

b, a

39

To where do inhibitory interneurons attach?

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

40

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

F. must be stimulated before

41

Inhibitory interneurons inhibit the initial synapse by releasing:

GABA

42

The release of GABA by the interneuron has what affect?

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

43

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

deactivation of Ca channels and activation of Ka channels

44

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

F. increase the rate of repolarization

45

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

decrease it

46

monosynaptic pathway is exc/ inh?

exc

47

Bisynaptic pathway is exc/inh?

inh

48

The Renshaw cell is mediated by:

'slow' and 'fast' postsynaptic transmission

49

Affect of RC on weakly excited MN in motor center:

inhibits

50

Affect of RC on strongly excited MN in motor center:

decreases firing rate (fine tunes muscle control)

51

This is involved in fine tune muscle control:

Renshaw cell

52

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

F. 1st part true, but induce IPSP's

53

This can lead to prolonged m. contraction:

No feedback control

54

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)

muscarinic, axon collaterals

55

What kind of receptors are at the NMJ?

nicotinic (AcH)

56

What type of receptor are at the interneuronal junction?

muscaarinic

57

T or F? Muscarinic is ionotropic.

F.

58

What affect will muscarinic receptors have on interneurons?

decrease K channels and increase the firing

59

acetylcholine receptors that form G protein-receptor complexes:

muscarinic AcH receptors

60

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

T

61

What affect will mAChR have on the RC cell?

stimulatory increase

62

The exc RC cell will release this once excited

glycine (feedback mechanism)

63

Excitation of interneuron leads to:

inhibition

64

Fast synaptic transmission will always activate:

the intrinsic ion channels

65

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

either

66

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

gly, AcH

67

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

axon collateral

68

What is the relationship between capacitance and resistance?

inversely related (check)