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
Q

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

A

ionotropic, metabotropic

2
Q

inflow of what ions will cause a cell to depolarize?

A

Na and Ca2+

3
Q

inflow of what ion will cause a cell to hyperpolarize?

A

Cl-

4
Q

outflow of what ion will cause a cell to hyperpolarize?

A

K+

5
Q

neurotransmitters modulate what part of the action potential?

A

the resting membrane potential

6
Q

neurotransmitters + receptors: short term changes are what?

A

changes in the membrane potential or postsynaptic cell

7
Q

neurotransmitters + receptors: long terms changes via what?

A

activation of signaling cascades

8
Q

IPSP stands for what?

A

inhibitory post synaptic potential

9
Q

EPSP stands for what?

A

excitatory post synaptic potential

10
Q

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

A

T

11
Q

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

A

F

12
Q

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

A

T

13
Q

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

A

T

14
Q

A few things about ionotropic receptors?

A
  • Involve direct opening of channel
  • Permeable to ions -> modulation of membrane potential
  • Na+, K+, Cl-, Ca2+
15
Q

A few things about metabotropic receptors?

A
  • Involve secondary messengers
  • involve metabolic pathways
  • G-Protein-coupled
16
Q

three groups of neurotransmitters?

A

amino acids, acetylcholine, monoamines

17
Q

amino acids include… (2 AAs)

A

GABA, Glutamate

18
Q

name 3 categories of monoamines and the drugs within those categories

A

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

19
Q

name a few other neurotransmitters

A

Histamine, Adenosine, Cannabinoids, Opioids, endorphins

20
Q

name 2 excitatory amino acids?

A

glutamate, aspartate

21
Q

name 2 inhibitory amino acids?

A

GABA, glycine

22
Q

what is the major excitatory NT in the CNS?

A

glutamate (green light on traffic light)

23
Q

what secretes glutamate?

A

pyramidal cells

24
Q

glutamate works in the ionotropic or metabotropic receptors?

A

both

25
Q

what processes does glutamate play major roles in?

A

synaptic plasticity and learning/memory

26
Q

excess glutamate can lead to what?

A

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

27
Q

three families of ionotropic glutamate receptors?

A

AMPA, NMDA, kainate

28
Q

NMDA glutamate receptor: what are antagonists?

A

Ketamine (“Special K”), PCP

29
Q

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

A

Glycine

30
Q

NMDA glutamate receptor: blocked by what?

A

Mg2+. Require depolarization to remove block

31
Q

NMDA glutamate receptor: permeable to what?

A

Ca2+

32
Q

NMDA glutamate receptor: critical for what?

A

synaptic plasticity, learning, memory

33
Q

what is the major inhibitory NT?

A

GABA. CNS depressant. remember stop sign.

34
Q

what receptors does GABA use?

A

GABAa, GABAb, GABAc

35
Q

a few important GABA drugs?

A

Benzodiazepines, Barbituates. Alcohol, General Anesthetics

36
Q

GABAa receptors: how many subunits?

A
  1. different drugs bind to different subunits.
37
Q

what is the mechanism for GABAa being a CNS depressant?

A

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

38
Q

GABAa typically used clinically for what?

A

Anti-anxiety, sedative, anticonvulsant, muscle relaxant

Treat anxiety, insomnia, seizures, alcohol withdrawal

39
Q

GABAb receptors: ionotropic or metabotropic?

A

metabotropic.

40
Q

GABAb accomplish what?

A

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

41
Q

GABAc receptors do what?

A

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

42
Q

GABAc receptors: ionotropic or metabotropic?

A

ionotropic

43
Q

GABAc receptors: high expression where?

A

High expression in retina, spinal cord and pituitary

44
Q

Acetylcholine: acts on what kind of receptors?

A

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

45
Q

what makes acetylcholine? what breaks it down?

A

ChAT (choline acetyl transferase) makes acetylcholine.

AchE breaks it down.

46
Q

Nicotinic receptors: open what channels? excitatory or inhibitory?

A

Opens Na+ Channels resulting in depolarization (EPSP)

47
Q

agonists of nicotinic receptors?

A

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

48
Q

Muscarinic receptors: which are found in CNS?

A

M1, M3, M4, M5

49
Q

muscarinic receptors: which are found in the heart?

A

M2

50
Q

muscarinic receptors: which are found in the smooth muscle?

A

M3

51
Q

muscarinic receptors: what are antagonists?

A

atropine (M1-M5), scopolamine (M1)

52
Q

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

A

atropine

53
Q

very potent AchE inhibitors?

A

organophosphates. cause SLUDGE, DUMBBELSS

54
Q

AchE inhibitors that are prescribed?

A

Donepezil
Tacrine
Galantamine
Rivastigmine

55
Q

what is the mechanism of action for Fluxotine?

A

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

56
Q

dopamine is made from what precursor?

A

tyrosine

57
Q

dopamine is degraded by what?

A

MAO and COMT

58
Q

re-uptake of dopamine is done by what?

A

dopamine transporter (DAT)

59
Q

dopamine activates what receptors?

A

D1-D5

60
Q

dopamine is produced where?

A

ventral tegmental area, substantia nigra

61
Q

dopamine is involved in what sorts of behaviors?

A

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

62
Q

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

A

D1 and D5. increases adenyl cyclase: excitatory.

63
Q

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

A

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

64
Q

How does Parkinson’s result from insufficient dopamine?

A

substantia nigra degenerates, less dopa sythesized

65
Q

treatment strategies for Parkinson’s? (4)

A

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

66
Q

give the chemical pathway that yields epinephrine from tyrosine

A

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

67
Q

what do antipsychotics do to the D2 receptor?

A

antagonize

68
Q

what does cocaine do to the dopamine receptor?

A

prevents dopamine reuptake

69
Q

what do amphetamines do to dopamine?

A

induce DA release

70
Q

what does Methylphenidate do to dopamine?

A

reuptake inhibitor

71
Q

norepinephrine: degraded by what?

A

MAO and COMT

72
Q

norepi: reuptake by what?

A

NET (Norepinephrine Transporter)

73
Q

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

A

Metabotropic (a1/b1 adrenergic receptors). agonist.

74
Q

norepi: produced where?

A

Locus Coeruleus, Caudal Raphe Nucleus

75
Q

norepi is main NT in what system

A

Main neurotransmitter in sympathetic system

76
Q

serotonin: made from what precursor?

A

L-tryptophan

77
Q

serotonin: degraded by what?

A

MAO

78
Q

serotonin: reuptake by what?

A

SERT (Serotonin Transporter)

79
Q

serotonin: activates what receptors?

A

5-HT 1-7 receptors

80
Q

serotonin: produced by what?

A

raphe nucleus (pons)

81
Q

histamine works at what receptors?

A

H1-H4

82
Q

H1 is important for what?

A

arousal (inhibit K channels) –> Antihistamines=drowsy

83
Q

adenosine does what to which channels?

A

inhibits Ca influx channels, activates K channels (antiarrythmic)

84
Q

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

A

CB1 and CB2. metabotropic (G-coupled).

85
Q

when activated, the CB1 receptor does what?

A

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

86
Q

anandamine: what does it do?

A

endogenous CB1 agonist. attenuates pain

87
Q

THC: what does it do?

A

exogenous CB1 agonist.

88
Q

name a few endogenous opioids?

A

Endorphins
Enkephalins
Dynorphins

89
Q

name a few drugs that are opioids?

A

morphine, heroin, codeine

90
Q

Baclofen is a selective agonist of what receptors?

A

GABAb. –> Antiplasticity in ALS and MS

91
Q

Is this receptor-drug pairing correct? GABA-Baclofen

A

Yes

92
Q

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

A

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

93
Q

Is this receptor-drug pairing correct? NMDA-Ketamine

A

Yes

94
Q

Is this receptor-drug pairing correct? AChR-Nicotine

A

Yes

95
Q

what can levodopa do that dopamine cannot?

A

cross the BBB

96
Q

what does carbidopa do?

A

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

97
Q

why is levodopa often administered with carbidopa?

A

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.