Neurotransmitter Systems III: Monoamines

Question 1

What are the monoamine systems involved in?

Answer 1

Motivation, reward, pleasure, movement, learning and cognition

Question 2

What disorders can be caused by disregulation of the monoamine system?

Answer 2

Depression, schitzophrenia, Parkinson’s and Alzheimer’s

Question 3

What are the central nervous systems that control behaviour?

Answer 3

Autonomic nervous system, hypothalamic-pituitary Neuro hormones and the diffuse monoamine system

Question 4

What are the four main systems within the diffuse modulatory system?

Answer 4

Nor-adrenergic locus coeruleus
serotonergic raphe nuclei
dopaminergic substantia niagra and ventral tegmental
cholinergic basal forebrain and brain stem complexes

Question 5

What are the common principles of the diffuse modulatory system?

Answer 5

Small set of neurons at the core,
Synapse from the brainstem
One neuron influences many others
Synapses release transmitter molecules into extracellular fluid

Question 6

How are the GABA and glutamate pathways characterised?

Answer 6

Point to point communication that is fast and widespread

Question 7

Give some examples of metabotropic receptors

Answer 7

5-HT1, 5-HT2, Dopamine D1, Dopamine D2, noradrenaline alpha 1 and 2

Question 8

What does 5-HT1 do?

Answer 8

Inhibits AC

Question 9

What does 5-HT2 do?

Answer 9

Stimulates PLC

Question 10

What does dopamine D1 do?

Answer 10

Stimulates AC

Question 11

What does dopamine D2 do?

Answer 11

Inhibits AC

Question 12

What does noradrenaline beta do?

Answer 12

Stimulates AC

Question 13

What does noradrenaline alpha1 do?

Answer 13

Stimulates PLC

Question 14

What does noradrenaline alpha2 do?

Answer 14

Inhibits AC

Question 15

Where is noradrenaline released from?

Answer 15

Adrenergic neurons that project from the locus coerulus

Question 16

What are the functions of noradrenaline?

Answer 16

Arousal, wakefulness, exploration and mood, blood pressure and addiction

Question 17

What is noradrenaline synthesised from?

Answer 17

Tyrosine

Question 18

What are the steps in noradrenaline synthesis?

Answer 18

Tyrosine ->
DOPA ->
Dopamine ->
Noradrenaline

Question 19

What enzyme converts tyrosine -> DOPA?

Answer 19

Tyrosine hydroxylase

Question 20

What enzyme converts DOPA -> dopamine?

Answer 20

DOPA decarboxylase

Question 21

What enzyme converts dopamine -> noradrenaline?

Answer 21

Dopamine beta-hydroxylase

Question 22

How does reserpine work?

Answer 22

Depletes noradrenaline stores by inhibiting vesicular uptake

Question 23

How do amphetamines work?

Answer 23

Enters vesicles displacing noradrenaline into the cytoplasm, which increases noradrenaline leakage out of the neuron into the synaptic cleft

Question 24

What type of receptors are all adrenergic receptors?

Answer 24

GPCR

Question 25

What are the noradrenergic receptors?

Answer 25

Alpha 1 and 2 and beta

Question 26

What does the alpha 2 noradrenergic receptor work on?

Answer 26

Inhibits adenyl cyclase and calcium

Question 27

What is noradrenaline broken down by inside the presynaptic neuron?

Answer 27

Monoamine oxidase

Question 28

What happens if there isnt enough noradrenaline?

Answer 28

Depressed state?

Question 29

What does too much noradrenaline cause?

Answer 29

Hyperaroused state

Question 30

If there is an excess of noradrenaline, what happens?

Answer 30

Taken up into the presynaptic neuron and broken down by monoamine oxidase

Question 31

What does cocaine block?

Answer 31

Noradrenaline reuptake

Question 32

How can we increase noradrenaline availability?

Answer 32

Block noradrenaline transporter and inhibit monoamine oxidase

Question 33

What is dopamine involved in?

Answer 33

Movement, reward, inhibition of prolactin release and memory consolidation

Question 34

What are the different pathways for dopamine release?

Answer 34

Nigrostriatal, Mesolimbic, mesocortical and tubero-hypophyseal

Question 35

Where does the nigrostriatal pathway project from and to?

Answer 35

Substantia nigra to the striatum

Question 36

What is the nigrostriatal pathway involved in?

Answer 36

Movement

Question 37

What disease affects the nigrostriatal pathway?

Answer 37

Parkinsons

Question 38

Where does the mesolimbic pathway project from and to?

Answer 38

From the ventral tegmental area to many brain areas (nucleus accumbens, amygdala and hippocampus)

Question 39

What is the mesolimbic pathway involved in?

Answer 39

Reward/pleasure

Question 40

What does hyperactivity of the mesolimbic pathway lead to?

Answer 40

Schizophrenia

Question 41

Where does the mesocortical pathway project from and to?

Answer 41

Ventral tegmental area to the frontal cortex

Question 42

What is the mesocortical pathway involved in?

Answer 42

Executive function

Question 43

What happens in the tubero-hypophyseal pathway?

Answer 43

Dopamine release from the hypothalamus into the pituitary

Question 44

What does the tuberohypophyseal pathway cause?

Answer 44

Inhibition of prolactin release

Question 45

What are the dopamine receptors in the chemoreceptor trigger zone involved in?

Answer 45

Triggering emesis

Question 46

Which dopamine receptors are in the D1-like family?

Answer 46

D1 and D5

Question 47

Which dopamine receptors are in the D2-like family?

Answer 47

D2,3 and 4

Question 48

What does the D1-like receptor family do?

Answer 48

Stimulate adenyl cyclase

Question 49

What does the D2-like receptor family do?

Answer 49

Inhibits adenyl cyclase and calcium influx and stimulates potassium efflux

Question 50

Where are the D1 and D2-like receptor families found?

Answer 50

Post synaptically

Question 51

Which is the only dopamine receptor to be found presynaptically?

Answer 51

D2

Question 52

What happens if you have a dopamine excess?

Answer 52

Reuptake by dopamine transporters, where it will be broken down by monoamine oxidase B

Question 53

How can you increase dopamine?

Answer 53

Give L-dopa Block dopamine transporters inhibit monoamine oxidase B

Question 54

What is another name for serotonin?

Answer 54

5-HT

Question 55

Where do the serotonin nerves project from?

Answer 55

Raphe nuclei to all over the brain

Question 56

What do the serotonin nerves do in the hypothalamus?

Answer 56

Reduce appetite

Question 57

What do the serotonin nerves do in the amygdala?

Answer 57

Elevate mood

Question 58

What do the serotonin nerves do in the cortex?

Answer 58

Heightened perceptions

Question 59

What do the serotonin nerves do in the spinal cord?

Answer 59

Suppress pain

Question 60

How does ecstasy work?

Answer 60

Increasing serotonin

Question 61

What is the synthesis pathway of serotonin?

Answer 61

Tryptophan -> 5-hydroxytrytophan -> 5-HT

Question 62

What type of receptors are the serotonin receptors?

Answer 62

All GPCRs apart from 5HT3

Question 63

Which is the only serotonin receptor to be found presynaptically?

Answer 63

5-HT 1D

Question 64

What does 5-HT 1D activation do?

Answer 64

Inhibits serotonin release

Question 65

What is acetylcholine involved in?

Answer 65

Memory, learning, motor control (striatum), reward and arousal

Question 66

What are illnesses that are related with acetylcholine issues?

Answer 66

Alzheimer's, pain, addiction, epilepsy, schizophrenia, ADHD, depression and anxiety

Question 67

Where do cholinergic neurons project from?

Answer 67

Nucleus basalis, septum, substantia nigra

Question 68

What is acetylcholine synthesised from?

Answer 68

Choline and acetyl CoA

Question 69

Where are ACh receptors found?

Answer 69

Both pre and postsynaptically

Question 70

What enzyme breaks ACh down?

Answer 70

Acetylcholine esterase

Question 71

What are the functions of histamine?

Answer 71

Sleep/wake and vomiting

Question 72

What are the functions of purines?

Answer 72

Sleep, pain, neuroprotection, addiction, seizures

Question 73

What are the functions of Neuro peptides?

Answer 73

Pain

Question 74

What are lipid mediators products of?

Answer 74

Conversion of eicosanoids to endocannabinoids

Question 75

What do lipid mediators act on?

Answer 75

CB1

Question 76

What is melatonin involved in?

Answer 76

Sleep regulation, circadian rhythm

Question 77

What are the theraputic uses of amphetamines?

Answer 77

ADHD

Question 78

What are the pharmacological effects of amphetamines?

Answer 78

Increased alertness and locomotor stimulation, euphoria, stereotyped behaviour, anorexia, decreased physical and mental fatigue, lack of tiredness

Question 79

What does cocaine do?

Answer 79

Blocks the dopamine transporters

Question 80

What are the pharmacological effects of cocaine?

Answer 80

Euphoria, locomotor stimulation, heightened pleasure

Question 81

How does MDMA work?

Answer 81

Inhibits monoamine transporters

Question 82

What does MDMA cause?

Answer 82

Increased serotonin and dopamine

Question 83

How does LSD/psilocybin work?

Answer 83

Hallucinogenic effect by acting on 5HT2 receptors