Exam 2: Monoamines

Question 1

2 types of monoamines - examples in each

Answer 1

indolamines (serotonin)

catecholamines (dopamine, norepinephrine, epinephrine)

Question 2

what neurotransmitters share a biosynthetic pathway

Answer 2

catecholamines (dopamine, epinephrine, norepinephrine

- all start with tyrosine

Question 3

catecholamine synthesis begins with the amino acid…

Answer 3

tyrosine

Question 4

what is the rate limiting enzyme for catecholamine sysnthesis?

Answer 4

tyrosine hydroxylase (TH)
- amount of dopamine depends on amount and activity of TH

Question 5

what converts dopa to dopamine

Answer 5

aromatic amino acid decarboxylase (AADC)

Question 6

what converts dopamine to norepinephrine

Answer 6

dopamine B-hydroxylase (DBH)

Question 7

what are catecholamines transported into vesicles by?

Answer 7

vesicular monoamine transporters (VMAT)

Question 8

what happens if DA and NE are not protected in vesicles?

Answer 8

they get broken down and levels drop causing sedation and depression

Question 9

VMAT blocker

Answer 9

Reserpine

• produces state of depression
• used in animals

Question 10

2 mechanisms of catecholamine inactivation

Answer 10

reuptake and enzymatic degradation

Question 11

reuptake of catecholamines

Answer 11

DA transporter and NE transporter bring DA and NE back into the cell
- molecules then repackages into vesicles or broken down

Question 12

what do antidepressants usually block?

Answer 12

NET and SERT

Question 13

what does cocaine inhibit?

Answer 13

reuptake of DA, NE, 5-HT

get build up in the synapse

Question 14

enzymatic degradation of catecholamines

Answer 14

COMT and MAO (MAOB)

Question 15

Dopamine metabolite in humans

Answer 15

homovanillic acid (HVA)

Question 16

NE metabolite

Answer 16

MHPG (3-methoxyl-4-hydroxy-phenylglycol in brain

VMA (vanillymandelic acid) in PNS

Question 17

2 families of dopamine receptors

Answer 17

all metabotropic

D1 family and D2 family

Question 18

D1 family of receptors

Answer 18

excitatory - inc adenylyl cyclase

includes D1 and D5

Question 19

D2 family of receptors

Answer 19

inhibitory - reduces adenylyl cyclase
D2, D3, D4
hyperpolarization

Question 20

DA autoreceptor

Answer 20

inhibitory - opens K+ channels, K+ exits cell
D2 receptor
presynaptic

Question 21

neurons that use dopamine are called

Answer 21

dopaminergic

Question 22

dopamine neuron cell bodies located in what 3 brain regions

Answer 22

ventral tegmental area
hypothalamus
substantia nigra

Question 23

4 dopamine pathways

Answer 23

mesolimbic dopamine system
mesocortical dopamine ssytem
tuberoinfundibular dopamine system
nigrostriatal dopamine system

Question 24

mesolimbic dopamine system

Answer 24

cell bodies in VTA project to the nucleus accumbens (ventral striatum)

Question 25

mesocortical dopamine system

Answer 25

cell bodies in VTA and project to the cerebral cortex

Question 26

tuberoinfundibular dopamine system

Answer 26

cell bodies in hypothalamus and axons project to pituitary (prolactin)

Question 27

nigrostriatal dopamine system

Answer 27

cell bodies in substantia nigra axons project to the striatum

Question 28

cells producing NE are referred to as

Answer 28

noradrenergic

Question 29

where are cell bodies of NE located?

Answer 29

locus coeruleus in the pons lateral tegmental system in the midbrain axons project all over forebrain

Question 30

NE systems modulate

Answer 30

mood, arousal, and sexual behavior

Question 31

what is NE?

Answer 31

a neurotransmitter and a hormone

Question 32

NE as a hormone?

Answer 32

released from adrenal glands and travels in bloodstream to target organs - CANNOT cross BBB

Question 33

release of NE effects on SNS

Answer 33

inc BP, inc HR, dec digestion, dilation of blood vessels to skeletal muscles, heart and brain

Question 34

all NE receptors are

Answer 34

metabotropic

Question 35

alpha NE receptors

Answer 35

a1-excitatory | a2-inhibitory - autoreceptor

Question 36

beta NE receptors

Answer 36

B1,2,3 all excitatory

Question 37

serotonin is an

Answer 37

indolamine

Question 38

most cell bodies of serotonin are located in

Answer 38

raphe nuclei (brainstem) and axons project through brain

Question 39

what is serotonin implicated in

Answer 39

sleep states, mood, sexual behavior, anxiety, hunger, aggression

Question 40

Prozac

Answer 40

increases serotonin activity

Question 41

serotonin is synthesized from what amino acid

Answer 41

tryptophan

Question 42

rate limiting step of serotonin

Answer 42

tryptophan hydroxylase (TPH) converting tryptophan to 5-hydroxytryptophan (5-HTP)

Question 43

what converts 5-HTP to 5-HT

Answer 43

AADC (aromatic amino acid decarboxylase)

Question 44

how is serotonin transported into vesicles

Answer 44

VMAT2

Question 45

Inactivation of serotonin: reuptake

Answer 45

reuptake by serotonin transporter (SERT)

Question 46

SSRis (selective serotonin reuptake inhibitors)

Answer 46

antidepressants | increase the amount of serotonin available

Question 47

serotonin inactivation: enzymatic breakdown

Answer 47

breakdown of 5-HT catalyzed by MAO-A | metabolite: 5-hydroxyindoleacetic acid (5-HIAA)

Question 48

ionotropic serotonin receptor

Answer 48

5-HT3

Question 49

inhibitory serotonin receptors

Answer 49

5-HT1 | 5-HT5

Question 50

serotonin autoreceptor

Answer 50

5-HT1A terminal autoreceptors- directly inhibit release somatodendritic autoreceptors-indirectly inhibit release by slowing rate of neuron firing

Question 51

Inhibitory 5-HT1AR expression

Answer 51

hippocampus, septum, amygdala, dorsal raphe, striatum | agonists reduce anxiety and pain

Question 52

Inhibitory 5-HT1BR expression

Answer 52

pain perception constricts blood vessels and blocks pain signals to ease pain in migraine sufferers agonists reduce food intake - anorexia

Question 53

excitatory 5-HT2AR expression

Answer 53

large amount in cerebral cortex | contribute to hallucinogenic effects of drugs (LSD)