5. Neurotransmitters and Receptors (Pharm) Flashcards Preview

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Flashcards in 5. Neurotransmitters and Receptors (Pharm) Deck (97)
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1

2 types of receptors we are concerned with in neuro pharm?

ionotropic, metabotropic

2

inflow of what ions will cause a cell to depolarize?

Na and Ca2+

3

inflow of what ion will cause a cell to hyperpolarize?

Cl-

4

outflow of what ion will cause a cell to hyperpolarize?

K+

5

neurotransmitters modulate what part of the action potential?

the resting membrane potential

6

neurotransmitters + receptors: short term changes are what?

changes in the membrane potential or postsynaptic cell

7

neurotransmitters + receptors: long terms changes via what?

activation of signaling cascades

8

IPSP stands for what?

inhibitory post synaptic potential

9

EPSP stands for what?

excitatory post synaptic potential

10

T/F: ionotropic receptors involve direct opening of ion channels

T

11

T/F: G-protein coupled receptors can be both ionotropic and metabotropic

F

12

T/F: Secondary messengers are required for signaling through metabotropic receptors

T

13

T/F: Na+ and K+ commonly pass through ion channel receptors to alter membrane potential

T

14

A few things about ionotropic receptors?

-Involve direct opening of channel
-Permeable to ions -> modulation of membrane potential
-Na+, K+, Cl-, Ca2+

15

A few things about metabotropic receptors?

-Involve secondary messengers
-involve metabolic pathways
-G-Protein-coupled

16

three groups of neurotransmitters?

amino acids, acetylcholine, monoamines

17

amino acids include... (2 AAs)

GABA, Glutamate

18

name 3 categories of monoamines and the drugs within those categories

Catecholamines (dopamine, NE, epi)
Histamine
Tryptamines (serotonin, melatonin)

19

name a few other neurotransmitters

Histamine, Adenosine, Cannabinoids, Opioids, endorphins

20

name 2 excitatory amino acids?

glutamate, aspartate

21

name 2 inhibitory amino acids?

GABA, glycine

22

what is the major excitatory NT in the CNS?

glutamate (green light on traffic light)

23

what secretes glutamate?

pyramidal cells

24

glutamate works in the ionotropic or metabotropic receptors?

both

25

what processes does glutamate play major roles in?

synaptic plasticity and learning/memory

26

excess glutamate can lead to what?

excitotoxicity (AD, ALS, neuropathic pain) - think burnout of the neurons

27

three families of ionotropic glutamate receptors?

AMPA, NMDA, kainate

28

NMDA glutamate receptor: what are antagonists?

Ketamine ("Special K"), PCP

29

NMDA glutamate receptor: requires what as a co-agonist to be activated?

Glycine

30

NMDA glutamate receptor: blocked by what?

Mg2+. Require depolarization to remove block

31

NMDA glutamate receptor: permeable to what?

Ca2+

32

NMDA glutamate receptor: critical for what?

synaptic plasticity, learning, memory

33

what is the major inhibitory NT?

GABA. CNS depressant. remember stop sign.

34

what receptors does GABA use?

GABAa, GABAb, GABAc

35

a few important GABA drugs?

Benzodiazepines, Barbituates. Alcohol, General Anesthetics

36

GABAa receptors: how many subunits?

3. different drugs bind to different subunits.

37

what is the mechanism for GABAa being a CNS depressant?

ionotropic receptor (ligand gated). GABA binds and opens Cl- channel. influx of Cl- into cell hyperpolarizes the cell and therefore prevents depolarization.

38

GABAa typically used clinically for what?

Anti-anxiety, sedative, anticonvulsant, muscle relaxant
Treat anxiety, insomnia, seizures, alcohol withdrawal

39

GABAb receptors: ionotropic or metabotropic?

metabotropic.

40

GABAb accomplish what?

Stimulates opening of K+ Channels, close Ca2+ channels. Efflux of K+ and decrease in Ca2+ conductance causes hyperpolarization of postsynaptic membrane (Inhibition)

41

GABAc receptors do what?

Opens Cl- Channels (inhibition when Cl- flows in due to hyperpolarization)

42

GABAc receptors: ionotropic or metabotropic?

ionotropic

43

GABAc receptors: high expression where?

High expression in retina, spinal cord and pituitary

44

Acetylcholine: acts on what kind of receptors?

Nicotinic Receptors (Ionotropic –Na+)
Muscarinic Receptors (Metabotropic)
-M1-M5
-G coupled (Slower excitation)

45

what makes acetylcholine? what breaks it down?

ChAT (choline acetyl transferase) makes acetylcholine.
AchE breaks it down.

46

Nicotinic receptors: open what channels? excitatory or inhibitory?

Opens Na+ Channels resulting in depolarization (EPSP)

47

agonists of nicotinic receptors?

Agonists:
nicotine: addictive, anxiolytic, analgesic, increases alertness
epibatidine, choline

48

Muscarinic receptors: which are found in CNS?

M1, M3, M4, M5

49

muscarinic receptors: which are found in the heart?

M2

50

muscarinic receptors: which are found in the smooth muscle?

M3

51

muscarinic receptors: what are antagonists?

atropine (M1-M5), scopolamine (M1)

52

what is the treatment/antidote for sarin/organophosphate poisoning?

atropine

53

very potent AchE inhibitors?

organophosphates. cause SLUDGE, DUMBBELSS

54

AchE inhibitors that are prescribed?

Donepezil
Tacrine
Galantamine
Rivastigmine

55

what is the mechanism of action for Fluxotine?

it is a SSRI: works at the serotonin reuptake receptor and inhibits reuptake.

56

dopamine is made from what precursor?

tyrosine

57

dopamine is degraded by what?

MAO and COMT

58

re-uptake of dopamine is done by what?

dopamine transporter (DAT)

59

dopamine activates what receptors?

D1-D5

60

dopamine is produced where?

ventral tegmental area, substantia nigra

61

dopamine is involved in what sorts of behaviors?

Involved in behavior, cognition, motor activity, motivation, reward, addiction

62

the D1 family of dopamine receptors includes what receptors? inh or excit?

D1 and D5. increases adenyl cyclase: excitatory.

63

the D2 family of dopamine receptors includes what receptors? inh or excit?

D2, D3, D4. increases phospodiesterase and produces inhibitory response

64

How does Parkinson's result from insufficient dopamine?

substantia nigra degenerates, less dopa sythesized

65

treatment strategies for Parkinson's? (4)

give L-Dopa (which is a Dopamine precursor)
give COMT inhibitors
give DOPA decarboxylase (acts on DOPA to produce dopamine)
give dopamine agonists

66

give the chemical pathway that yields epinephrine from tyrosine

Tyrosine -> DOPA -> Dopamine -> norepinephrine -> Epinepnrine

67

what do antipsychotics do to the D2 receptor?

antagonize

68

what does cocaine do to the dopamine receptor?

prevents dopamine reuptake

69

what do amphetamines do to dopamine?

induce DA release

70

what does Methylphenidate do to dopamine?

reuptake inhibitor

71

norepinephrine: degraded by what?

MAO and COMT

72

norepi: reuptake by what?

NET (Norepinephrine Transporter)

73

norepi: works at what receptors? what kind of receptors are they?

Metabotropic (a1/b1 adrenergic receptors). agonist.

74

norepi: produced where?

Locus Coeruleus, Caudal Raphe Nucleus

75

norepi is main NT in what system

Main neurotransmitter in sympathetic system

76

serotonin: made from what precursor?

L-tryptophan

77

serotonin: degraded by what?

MAO

78

serotonin: reuptake by what?

SERT (Serotonin Transporter)

79

serotonin: activates what receptors?

5-HT 1-7 receptors

80

serotonin: produced by what?

raphe nucleus (pons)

81

histamine works at what receptors?

H1-H4

82

H1 is important for what?

arousal (inhibit K channels) --> Antihistamines=drowsy

83

adenosine does what to which channels?

inhibits Ca influx channels, activates K channels (antiarrythmic)

84

cannbinoids work though what receptors? what types of receptors are these?

CB1 and CB2. metabotropic (G-coupled).

85

when activated, the CB1 receptor does what?

inhibits GABA and glutamate release. effect varies depending on brain region.

86

anandamine: what does it do?

endogenous CB1 agonist. attenuates pain

87

THC: what does it do?

exogenous CB1 agonist.

88

name a few endogenous opioids?

Endorphins
Enkephalins
Dynorphins

89

name a few drugs that are opioids?

morphine, heroin, codeine

90

Baclofen is a selective agonist of what receptors?

GABAb. --> Antiplasticity in ALS and MS

91

Is this receptor-drug pairing correct? GABA-Baclofen

Yes

92

Is this receptor-drug pairing correct? 5-HT-Fluoxetine

No, fluoxetine inhibits the re-uptake receptor (SERT)

93

Is this receptor-drug pairing correct? NMDA-Ketamine

Yes

94

Is this receptor-drug pairing correct? AChR-Nicotine

Yes

95

what can levodopa do that dopamine cannot?

cross the BBB

96

what does carbidopa do?

it is a peripheral decarboxylase inhibitor - inhibits the formation of dopamine from its precursors

97

why is levodopa often administered with carbidopa?

levodopa is given to cross the BBB, and it is converted to dopamine in the brain. carbidopa is given along with it to inc the availability of L-dopa in the brain and limit peripheral side effects.