Lecture 7

Question 1

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

Answer 1

T

Question 2

Why is the AP threshold lowest at the trigger zone?

Answer 2

more Na channels

Question 3

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

Answer 3

T

Question 4

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

Answer 4

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

Question 5

What determines relative efficacy of input to create an AP?

Answer 5

proximity to synapse

Question 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.

Answer 6

F. vice versa

Question 7

How are synaptic potentials integrated?

Answer 7

spatially and temporally

Question 8

These are the dominant player after threshold is reached?

Answer 8

Voltage gated Na channels

Question 9

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

Answer 9

CNS, NMJ

Question 10

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

Answer 10

glutamate, AcH (and glutamate)

Question 11

Why can synaptic pot’s increase temporal?

Answer 11

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

Question 12

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

Answer 12

Ca

Question 13

There ___ times more Ca outside the cell than inside.

Answer 13

10,000

Question 14

Why will low freq stimulation generate the same size EPSP?

Answer 14

Ca had time to return to baseline

Question 15

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

Answer 15

F. Both EPSP and IPSP

Question 16

Can inhibition be presyn, postsyn, or either.

Answer 16

either

Question 17

Postsynaptic inhibition is mediated by:

Answer 17

GABA(aR)

Question 18

What molecule is used in postsynaptic inhibition?

Answer 18

Cl- (GABA is a chloride channel)

Question 19

What affect postsyn inhibition have on an EPSC?

Answer 19

shunt and reduce the efficacy

Question 20

Where are postsyn inhibitory synapses located?

Answer 20

dendritic shaft of cell body near AP trigger zone

Question 21

T or F? Inhibitory synapses can only work locally.

Answer 21

T

Question 22

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

Answer 22

T

Question 23

Where does presynaptic inhibition usually occurs?

Answer 23

at axon-axonic synapse

Question 24

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

Answer 24

size decreases

Question 25

What type of channel does presynaptic inhibition target?

Answer 25

Ca channels

Question 26

What type of receptor is involved with presynaptic inhibition?

Answer 26

GABA(b)

Question 27

What type of receptor is GABA(b)?

Answer 27

metabotropic receptor

Question 28

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

Answer 28

decrease Ca channels

Question 29

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

Answer 29

F. Decreases

Question 30

Another term for amount of T released:

Answer 30

quantal content

Question 31

In which pathways does presynaptic inhibition play a prominent role?

Answer 31

sensory system pathways

Question 32

presynaptic inhibition plays this role in sensory system pathways:

Answer 32

habituation

Question 33

Define habituation:

Answer 33

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

Question 34

Principle T of presynaptic inhibition:

Answer 34

GABA

Question 35

These neurotransmitters regulate diverse populations of neurons:

Answer 35

neuromodulators

Question 36

Each T has only one specific type of receptor.

Answer 36

F. Can have diff receptors

Question 37

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

Answer 37

T

Question 38

Presynaptic uses GABA__ and postsynaptic uses GABA___.

Answer 38

b, a

Question 39

To where do inhibitory interneurons attach?

Answer 39

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

Question 40

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

Answer 40

F. must be stimulated before

Question 41

Inhibitory interneurons inhibit the initial synapse by releasing:

Answer 41

GABA

Question 42

The release of GABA by the interneuron has what affect?

Answer 42

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

Question 43

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

Answer 43

deactivation of Ca channels and activation of Ka channels

Question 44

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

Answer 44

F. increase the rate of repolarization

Question 45

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

Answer 45

decrease it

Question 46

monosynaptic pathway is exc/ inh?

Answer 46

exc

Question 47

Bisynaptic pathway is exc/inh?

Answer 47

inh

Question 48

The Renshaw cell is mediated by:

Answer 48

'slow' and 'fast' postsynaptic transmission

Question 49

Affect of RC on weakly excited MN in motor center:

Answer 49

inhibits

Question 50

Affect of RC on strongly excited MN in motor center:

Answer 50

decreases firing rate (fine tunes muscle control)

Question 51

This is involved in fine tune muscle control:

Answer 51

Renshaw cell

Question 52

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

Answer 52

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

Question 53

This can lead to prolonged m. contraction:

Answer 53

No feedback control

Question 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)

Answer 54

muscarinic, axon collaterals

Question 55

What kind of receptors are at the NMJ?

Answer 55

nicotinic (AcH)

Question 56

What type of receptor are at the interneuronal junction?

Answer 56

muscaarinic

Question 57

T or F? Muscarinic is ionotropic.

Answer 57

F.

Question 58

What affect will muscarinic receptors have on interneurons?

Answer 58

decrease K channels and increase the firing

Question 59

acetylcholine receptors that form G protein-receptor complexes:

Answer 59

muscarinic AcH receptors

Question 60

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

Answer 60

T

Question 61

What affect will mAChR have on the RC cell?

Answer 61

stimulatory increase

Question 62

The exc RC cell will release this once excited

Answer 62

glycine (feedback mechanism)

Question 63

Excitation of interneuron leads to:

Answer 63

inhibition

Question 64

Fast synaptic transmission will always activate:

Answer 64

the intrinsic ion channels

Question 65

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

Answer 65

either

Question 66

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

Answer 66

gly, AcH

Question 67

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

Answer 67

axon collateral

Question 68

What is the relationship between capacitance and resistance?

Answer 68

inversely related (check)