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Flashcards in CNS Neurotransmitters Lec05 Deck (88):
1

What are the small molecule NT? *

1. ach.

2. amino acids -- glutamate, gaba, glycine

3. biogenic amines -- dopamine, norepinephrine, serontonin

2

what are the amiunoacid NT?

gaba, gluamate, glycine

3

what are the biogenic amine NT?

dopamine, norepinephrine, serotonin

4

how many different neuropeptides are there

more than 100 different peptides

5

neuropeptides are typically ___ amino acids long 

3-36

6

what are the two major classes of NT?

small moelcule and neuropetides

7

The concentration of neurotransmitter within the synaptic cleft is tightly controlled via regulation of:

synthesis, packaging, release, and removal

8

where are small moelcule NT made?

presynaptic terminal

9

how are small NT packaged into vesicles?

by specific transport proteins in the vesicle membrane

10

where are neuropeptide NT made and packaged?

within the cell body

11

how are vesicles of enruopeptides transported to the nerve terminal?

via fast axonal transport

12

___ neurotransmitters can respond very rapidly?

small molecule

 

are right there in the synaptic terminal to respond quickly

13

___ neurotransmitter release must be carefully regulated to prevent depletion.

neuropeptide

14

ionotropic receptors are ____ gated ion channels that open in response to ligand bonding

ligand gated

15

how many subunits do ionotropic chanels contain? how many transmembrane domains does each subunit contain?

5 subunits; 3-4 transmembrane domains

16

how is diversity established with ionotropic NT?

muleiple subunits are assembled in different orders

17

metabotropic coupled receptors activate ___ in response to ligand binding

g-proteins

18

 activated G-proteins modulate ion channels either

directly or indirectly

19

how many transmembrane domains does each monmeric metabotropic receptor have?

7 transmembrane domains

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20

what are the functions of acetylcholine in the CNS?

Attention, arousal, reward plasticity.
Enhances sensory functions upon waking

memory

21

Damage to cholinergic system is associated with the ___

memory defecits in AD

22

where is acetylcholien found in the peripheral NS?

NMJ

synapses in ganglia of the visceral motor system 

23

how is AcH synthesized? 

 enzymatically in nerve terminal from acetyl-CoA and
choline

24

how is acetylcholine removed from the synaptic cleft?

via cleavage to acetate and choline by acetylcholinesterase

25

after degradation, how is more acetylcholine made? 

choline is taken up by nerve terminal via a specific transporter and is used to synthesize more Ach

26

how are Organophosphates such as some insecticides  and nerve gas hamrful to humans?

 inhibit acetylcholinesterase causing ACh to accumulate at cholinergic synapses.

27

what is the result of organophasopates (nerve gases and insectisides) causing acetylcholine build up at the NMJ?

causes muscle paralysis 

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28

___ ach receptors mediate most acetylcholine effects in the brain?

metabotropic

29

scopolamine and atropine are

metabotropic achetylcholine anatagonists

30

what are the symptoms of myasthenia gravis?

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31

with myasthenia gravis, patients have antibodies against

nicotinic acetylcholien receptors

32

how is the structure of the NMJ altered in myasthenia gravis

1. dec concentration of acetylcholine receptors in postsynpatic membrane

2. sparse and shallow junctional folds

3. expanded synaptic cleft

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33

size of ___ and ___ is reduced with myasthenia gravis

mini endplate potentials and endplate potentials

34

with myasthenai gravis, what is different during repeated stimualtion

the compound AP will be decreased in size (fatigue)

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35

the probability of what is reduced with myasthenia gravis?

that a presynaptic AP will elicit a postsynatpci actioin potential

36

what does the tx of mysathenia gravis include?

cholinersterase inhbiitors

thyemactomy

corticoseteroids

immunosuppressants

37

____ is the most prominent NT for normal brain function

glutamate

(more than half of all brain synapses use glutamate)

38

____ has been shown to slowglutamate reuptake --> raising potential for neuroexoticity

oxygen depirvation

39

why is glutamine important? 

glutamate cannot cross blood brain barrier, but glutamine can

40

how and where is gltuamate synthesized?

in the nerve terminal from

1. glutamine

2. the transamination of a-ketoglutarate

41

how is glutamate removed from the synaptic cleft? 

 by high affinity glutamate transporters on both the nerve terminal and nearby glial cells

42

what do glial cells do with gltuamate sucked up from the synaptic cleft? 

glutamate is converted into glutamine and then transported out of the cell and back into nerve terminals

43

___ binding is required to open NMDA channel

glycine

44

__ ions can pass through NMDA channels

ca

45

Gaba is widely used where

1. in the brain -- 1/3 of all brain synapses use gaba

2. in local interneurons and purkinje cells of cerebellum

 

46

where is glyceine mostly used?

in the synapses in the spinal cord

47

how is gaba synthesize?

in nerve terminals from glutamate 

48

what is needed for gaba to be made from glutamate?

 pyridoxal phosphate (PLP) derived from vitamin B6

49

how is gaba removed from the synaptic cleft?

 by specific transporters on nerve terminals and nearby glia

50

decreased gaba function can cause

epilepsy

51

how is glyceine synthesized?

in nerve terminals from serine

52

how is glycine removed from the synaptic cleft

 by specific transporters on nerve terminals and nearby glia

53

how can there be excess glycine? what can thise cause

 defects in the glycine transporter  can cause excessive glycine

 

excess glycine --> neonatal disease characterized by lethargy and mental retardation

54

strychnine is a 

glyceine receptor anatognist

55

what are the effects of strychine

blocks gaba ionotropic receptors --> leads to overacitity int he spinal cord and brainstem --> seizures

56

where are the biogenic amines made

in nerve terminals

57

what packages the biogenic amines

vesicualr monoamine transporter (VMAT)

58

how are the biogenic amines removed from the synaptic cleft

reuptake into nerve terminals

59

what types of receptors do the biogenic amines ahve?

- have metabotropic 

- serotonin has ionotropic as well

60

how is dopamine made?

tyrospine --> dopa ---> dopamine

61

how is norepinephrine made?

tyrospine --> dopa ---> dopamine --> norepinephrine

62

how is epinephtrine made?

tyrospine --> dopa ---> dopamine --> norepinephrine --> epinpeinphrine

63

80% of brain dopamine found in ___

corpus striatum (which receives major input from the substantia nigra)

64

midbrain dopamine system projections from the

ventral tegmental area to ventral parts of the striatum

65

what is the midbrain dopamien system invovled in

motivation, reward, reinforcement

66

what are doipamine projections tot he cortex involved in

emotional behavior

67

norepinephrine neurons from the locus coerelus project to

forebriana nd brainstem targets

68

what is the major transmitter of the sympathetic motor system

norepinehprine

69

catehcolimine receptors are all

metabotropic

70

anatagonists of ___ receptors in the medulla are sued as antiemtics

dopamine

71

dopamine receptors act by 

activiating or inhbiitng adenyl cyclase

72

dopamine blocks dopamine transports causing

 a net increase in release of doapmine

73

ampohetamine inhbiits both dopamine and norepeinphrine causing a

net increase in release of dopamine and norepinephrine

74

raphe nuclei in the upper brainstem project to

forebrain and also to the brainstem

75

how is serotonin transported back into the nerve terminal

by specific serotonin transporter or (SERT)

76

metabotropic recpeotrs of serotonin are involved in

emotions, circadian rhtyms, motor behaviors, mental arousal

77

activation of ___ mediates satiety and decreased food consumption

metabotropic serotonergic receptors

78

MAO inhbiitors block the breakdown of

biogenic amines

79

tricyclic antidperessants block the reuptake of

norepeinhprine and serotonin

80

peptide NT are implicated in modulating

emotions, perceptions of pain, and repsonses to stress

81

how are neuropeptides made?

synthesized as pre-propetides in the er in the cell body

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82

what are peptide nt sometimes co released with

small molecule NT

83

how are neuropeptides degraded in the synaptic cleft

1. removed by peptidases which degrade them

2. degraded to more activ epeptides by endopeptidases

84

metabotropic receptors of peptide NT are activated at ___ peptide concnetrations

relatively low

85

morphine binds to the same receptors are

opoiud peptides

86

which NT have just iontropic receptors

glyceine

87

what are the main functions of dopamine

coordiantion of body movement, movtivation, reward reinforcement

emotional behavior

88

what can cause a neonatal disease characterized by lethargy and mental retardation?

excess glycine