ANS Harvey Part 2

Question 1

Function of the Autonomic Nervous System relies on the transmission of information from a presynaptic neuron to a postsynaptic cell. This process involves chemical transmission. WHen is this true?

Answer 1

ALWAYS!

Question 2

Explain the 7 steps of chemical synaptic transmission for Norepinephrine

Answer 2

1) Action potential arrives at varicosity
2) Depolarization opens voltage-gated Ca2+ channel
3) Ca2+ entry tiggers exocytosis of synaptic vesicle
4) NE binds to adrenergic receptor on target
5) Activity ceases when NE diffuses away from the synpase
6) NE is transported back into the axon
7) NE can be taken back into synaptic vesicles for re-release or NE is metabolized by monoamine oxidase (MAO)

Question 3

Ca2+ is lower (blank) the cell than it is (blank) the cell, Ca moving in down its gradient causes fusion of synaptic vesicle to the presynaptic membrane

Answer 3

inside, outside

Question 4

Not all postsynaptic responses are the same, the difference is (blank)

Answer 4

speed

Question 5

Post synaptic responses vary

depending on the (blank)

Answer 5

signaling mechanism

Question 6

Some neurotransmitters receptors are a ligand receptor and a (blank) receptor in one (i.e. it opens calcium channel). Other’s can bind are a ligand binding receptor with a separate (blank).

Answer 6

ion channel

Question 7

If a neutrotransmitter receptor ion channel is separate from the ligand binding receptor it does not always activate ion channels, and it can modify downstream effectors
T or F?

Answer 7

True

Question 8

What is chemical transmission?
What is evidence of this?
Why is this important?

Answer 8

the ability to utilize the chemical environment to elicit a response in an organ.
The ability to stimulate a response in the heart by stimulating a different heart and taking the chemical environment of that heart and placing it in the other.
(you will get a delayed response in the chemically stimulated heart)
Basis for all pharmacology!

Question 9

Most synaptic responses are (blank).

Answer 9

chemical

Question 10

What does atropine block, what can it be used for?

Answer 10

blocks synapse to muscarine receptors resulting in pupil dialation

Question 11

What does curare block?

Answer 11

ACh from binding to Nicotine muscular receptors resulting in inability to move.

Question 12

What is the criteria for neurotransmitter identification?

Answer 12

presence, release, identity of action, removal

Question 13

For the criteria for neurotransmitter identification, what must be present?

Answer 13

the substance must be present in the presynaptic nerve terminal

Question 14

For the criteria for neurotransmitter identification, what must be released?

Answer 14

the substance must be released in response to presynaptic depolarization, and the release must be Ca2+-dependent.

Question 15

For the criteria for neurotransmitter identification, what must be the identity of action?

Answer 15

direct application of the substance to the postsynaptic cell must produce the same response as stimulation of the presynaptic neuron. Likewise, compounds that block the response produced by stimulation of the presynaptic neuron must also block the response produced by direct application of the putative neurotransmitter.

Question 16

For the criteria for neurotransmitter identification, what must be the removal?

Answer 16

there must be one or more mechanisms for elimination of the substance from the synaptic cleft.

Question 17

What transmitter is at:

• neuromuscular junction (somatic motor neuron and skeletal muscle)
• all autonomic ganglia (both sympathetic and parasympathetic)
• all parasympathetic postganlionic neuoreffector junctions
• select sympathetic postganglionic neuroeffector junctions (sweat glands)
• between sympathetic preganglionic neurons and adrenal chromaffin cells
• certain central nervous system synapses

Answer 17

acetylcholine (ACh)

Question 18

What transmitter is at:

• neurotransmitter at postganglionic sympathetic neuroeffector junctions
• neurotransmitter at certain central nervous system synapses

Answer 18

Norepinephrine (NEpi) is the neurotransmitter at:

Question 19

chemical transmission involving NEpi also referred to as (blank)

Answer 19

noradrenergic

Question 20

What transmitter is at:

• as a hormone from adrenal chromaffin cells
• as neurotransmitter at certain central nervous system synapses

Answer 20

Epinephrine (Epi)

Question 21

What transmitter is at:

• at postganglionic sympathetic neuroeffector junctions in the kidney
• at certain central nervous system synapses

Answer 21

Dopamine (DA)

Question 22

Chemical transmission involving DA also referred to as (blank).

Answer 22

dopaminergic

Question 23

(blank) is important in regulating blood vessels in the kidney?

Answer 23

dopamine

Question 24

Besides adrenergic, and cholinergic, are there other chemical transmissions that are used? What is an important example?

Answer 24

yes

ATP

Question 25

``` What are these: Putative NANC transmitters: adenosine 5’-triphosphate (ATP) vasoactive intestinal peptide (VIP) neuropeptide Y (NPY) leutinizing hormone releasing hormone (LHRH) 5-hydroxy tryptamine (5-HT or serotonin) nitric oxide (NO) gamma-amino butyric acid (GABA) substance P dopamine ```

Answer 25

Nonadrenergic noncholingergic transmission

Question 26

Most neurons actually release (blank) substances.

Answer 26

multiple

Question 27

Don’t aways get release of a single neurotransmitter from any given vessicle, you tend to have many different transmitters in any given vesicle that are released together. These are referred to as (blank) .

Answer 27

cotransmitters

Question 28

What are the key steps in the life cycle of a neurotransmitter?

Answer 28

``` synthesis storage release receptor interaction disposition ```

Question 29

acetylcholine is made from (blank) and acetyl coa

Answer 29

choline

Question 30

In the synaptic cleft, ACh is rapidly broken down by the enyzme (blank)

Answer 30

(acetylcholinesterase)

Question 31

In the synaptic cleft, ACh is rapidly broken down by the enyzme acetylcholinesterase, (blank) is then transported back into the axon terminal and is used to make more ACh/

Answer 31

choline

Question 32

ACh is transported into vesicles by the (blank)

Answer 32

vesicle-associated transporter (VAT)

Question 33

ACh is released when Ca2+ influx into nerve terminal facilitates vesicular fusion by docking proteins: ???

Answer 33

synaptosome associated proteins (SNAPs) | vesicle-associated proteins (VAMPs)

Question 34

Once released into the synaptic cleft, ACh can either bind to (blank) receptors on the postsynaptic membrane, or be broken down by acetylcholinesterase (AChE) into choline and acetate

Answer 34

nicotinic or muscarinic

Question 35

AChE (acetylcholinesterase) is located on the (blank) membrane

Answer 35

postsynaptic

Question 36

Choline can then be recycled by transport back into the presynaptic nerve terminal by the (blank)

Answer 36

Na+-dependent choline transporter (CHT)

Question 37

(blank) inhibits the Na+-dependent choline transporter (CHT) | Choline can not be transported and recycled

Answer 37

hemicolinium

Question 38

(blank) inhibits the vesicle-associated transporter (VAT) | Inhibits the transport of ACh into the vesicle

Answer 38

vesamicol

Question 39

(blank) toxin blocks exocytosis by modifying vesicle docking proteins: synaptasome associated proteins (SNAPs) vesicle-associated membrane proteins (VAMPs)

Answer 39

botulinum

Question 40

SNAPS and VAMPS are under a categorey called what?

Answer 40

SNARES

Question 41

SNARE proteins are blocked by what? VAMPs (vesicle associated membrane proteins) synaptobrevin SNAPs (synaptosome associated proteins) syntaxin SNAP 25

Answer 41

Botox

Question 42

IS synatptobrevin a VAMP or SNAP?

Answer 42

VAMP

Question 43

Is syntaxin and SNAP 25 a Vamp or a SNAP?

Answer 43

SNAP

Question 44

ACh is an agonist for what?

Answer 44

Nicotinic and muscarinic receptors

Question 45

Nicotine is an agonist for what?

Answer 45

nicotinic receptors

Question 46

Behtanacol is an agonist for what?

Answer 46

muscarinic receptors

Question 47

trimethaphan is an antagonist for what?

Answer 47

neuronal nicotinic receptors (Nn)

Question 48

d-tubocurarine is an antagonist for what?

Answer 48

muscle nicotinic receptors

Question 49

atropine is an antagonist for what?

Answer 49

muscarinic receptors

Question 50

Are any compounds truly specific?

Answer 50

no, most compounds can bind to a variety of things

Question 51

Which do you use more often to describe drugs, selectivity or specificity?

Answer 51

selectivity

Question 52

What is the likelihood to bind to one receptor over another?

Answer 52

selectivity

Question 53

(blank) inhibits acetycholinesterase which enhances response of acetylcholine transmission

Answer 53

neostigmine

Question 54

What is the rate limiting enzyme in adrenergic synapses?

Answer 54

tyrosine hydroxylase

Question 55

Tyrosine is taken up into the presynaptic nerve terminal by a Na-dependent amino acid transporter (A) where it is then converted to (blank) by the rate limiting enzyme tyrosine hydroxylase.

Answer 55

DOPA

Question 56

(blank) is taken up into the presynaptic nerve terminal by a Na-dependent amino acid transporter (A) where it is then converted to DOPA by the rate limiting enzyme tyrosine hydroxylase.

Answer 56

Tyrosine

Question 57

DOPA is then converted to(blank) by the enzyme DOPA decarboxylase (also called dopamine decarboxylase).

Answer 57

dopamine

Question 58

Dopamine is then transported into vesicles by (blank) .

Answer 58

vesicular monoamine transporter (VMAT)

Question 59

The predominant adrenergic neurotransmitter released depends on what (blank) are present in the vesicles.

Answer 59

enzymes

Question 60

In the presynaptic nerve terminal of most postganglionic adrenergic neurons in the ANS, dopamine is converted to norepinephrine by (blank)

Answer 60

dopamine beta-hydroxylase.

Question 61

In (blank), norepinephrine is converted to epinephrine by phenylethenolamine N-methyltransferase (PNMT).

Answer 61

chromaffin cells

Question 62

Once released into the synaptic cleft, norepinephrine (NE) can either bind to pre or postsynaptic adrenergic receptors be taken up by the presynaptic nerve terminal or other cells (extraneuronal) OR.....

Answer 62

diffuse out of the cleft

Question 63

Neurotransmitter taken up by the presynaptic nerve terminal (primary mechanism) can be transported back into vesicles by the (blank) or metabolized by (blank)

Answer 63

VMAT, or | metabolized by monoamine oxidase (MOA)

Question 64

Neurotransmitter taken up extraneuronally can be metabolized by (blank).

Answer 64

MAO and COMT

Question 65

Neurotransmitter not taken up is metabolized primarily by COMT found in the (blank).

Answer 65

liver

Question 66

What are the 2 enzymes important in breaking down catecholamines?

Answer 66

MAO (monoamine oxidase) | COMT (catechol-O-methyl transferase)

Question 67

(blank) inhibits tyrosine hydroxylase (can be used to treat certain types of hypertension)

Answer 67

α-methyltyrosine

Question 68

(blank) inhibits the vesicular monoamine transporter (VMAT) (cant get transported into vesicle)

Answer 68

reserpine

Question 69

(blank) inhibits the nerve action potential preventing Ca2+ influx

Answer 69

bretylium

Question 70

(blank) is taken up into nerves by the NET. It then gets concentrated in the synaptic vesicles, displacing endogenous sympathetic neurotransmitters. (inhibits norepinephrine release, indirect NE antagonist)

Answer 70

guanethadine

Question 71

(blank) inhibits catecholamine release by activating α2 receptors on the presynaptic nerve terminal.

Answer 71

clonidine

Question 72

What drug affects adrenergic transmission synthesis? Storage? Release? Disposition?

Answer 72

α-methyltyrosine reserpine bretylium, guanethadine, and clonidine entacapone, pargyline, cocaine, amphetamines

Question 73

What drug affects cholinergic transmission synthesis? Storage? Release? Disposition?

Answer 73

hemicolinium vesamicol botulinum toxin neostigimine

Question 74

oxymetazoline is an agonist for what?

Answer 74

α1 and α2 receptors (“non-selective”)

Question 75

phenylephrine is an agonist for what?

Answer 75

α1 receptors (“selective”)

Question 76

clonidine is an agonist for what?

Answer 76

α2 receptors

Question 77

phentolamine is an antagonist for what?

Answer 77

α1 and α2 receptors

Question 78

prazosin is an antagonist for what?

Answer 78

α1 receptors

Question 79

yohimbine is an antagonist for what?

Answer 79

α2 receptors

Question 80

isoproterenol is an agonist for what?

Answer 80

β1 and β2 receptors

Question 81

dobutamine is an agonist for what?

Answer 81

β1 receptors

Question 82

terbutaline is an agonist for what?

Answer 82

β2 receptors

Question 83

propranolol an antagonist for what?

Answer 83

β1 and β2 receptors

Question 84

Metoprolol isan antagonist for what?

Answer 84

β1 receptors

Question 85

inhibits catechol-O-methyl transferase (COMT)

Answer 85

entacapone

Question 86

inhibits monoamine oxidase (MAO)

Answer 86

paragyline, phenelzine

Question 87

inhibit neuronal reuptake by the norepinephrine transporter (NET)

Answer 87

cocaine, amphetamines

Question 88

MAO and COMT breakdown (blank)

Answer 88

catecholamines