neuropeptides

Question 1

true or false - there are more neuropeptides than neurotransmitters

Answer 1

true

Question 2

neuropeptides are similar in design and function to peptide hormones in the ______ (what two systems)

Answer 2

pituitary and GI

Question 3

polypeptide precursors are called what

Answer 3

propeptides and pre-propeptides

Question 4

true or false - neuropeptides are bigger than proteins

Answer 4

false - they are smaller than proteins

Question 5

where does peptide synthesis occur

Answer 5

in the cell body

Question 6

what do pre-propeptides contain

Answer 6

a series of hydrophobic amino acids at the N-terminus

Question 7

how is the signal sequence cleaved in pre-propeptide sequencing and what is the result of this

Answer 7

a signal peptidase -> results in an inactive propeptide

Question 8

how are propeptides packaged for transport

Answer 8

in large dense core vesicles

Question 9

what is the significance of POMC

Answer 9

it is a gene that produces a propeptide for melanocyte stimulating hormones, ACTH, beta endorphins, LPH and corticotropin like intermediate peptides

Question 10

propeptide cleavage is done by what enzyme

Answer 10

synthesizing peptidase

Question 11

what is the function of catabolic peptidases

Answer 11

cleave active peptides -> inactive
extracellular

Question 12

catabolic peptidases are usually ______ peptidases while signalling/synthesizing peptidases are ____ peptidases

Answer 12

exo / endo

Question 13

what is the difference in synthesis between neurotransmitter and neuropeptide

Answer 13

transmitter -> nerve terminal
peptide -> cell body

Question 14

what is the difference in release between neurotransmitter and neuropeptide

Answer 14

transmitter -> released by synaptic vesicles by exocytosis
peptide -> released from synthetic peptidases by exocytosis

Question 15

what is the difference in reuptake between neurotransmitter and neuropeptide

Answer 15

transmitter -> recycled at nerve terminal
peptide -> degraded

Question 16

what is the difference in concentrations between neurotransmitter and neuropeptide

Answer 16

transmitter -> high concentrations at nerve terminal
peptide -> low concentration at nerve terminal

Question 17

what type of receptors are neuropeptides

Answer 17

G protein coupled

Question 18

neuropeptide release can ____ or _____ actions of primary neurotransmitters

Answer 18

strengthen or prolong

Question 19

neuropeptides have five types of functions , what are they

Answer 19

1. direct action
2. autocrine
3. juxtacrine
4. paracrine
5. endocrine

Question 20

what does CART stand for

Answer 20

cocaine and amphetamine regulated transcript

Question 21

what are the 5 types of neuroactive peptides and provide examples if possible

Answer 21

tahcykinin -> substance P
cholecystokinin -> CCK
CART
orexigenic peptides -> neuropeptide Y, ghrelin and orexin
oxytocin and vasopressin

Question 22

what is one of the earliest neuroactive peptides

Answer 22

tachykinin peptides -> substance P

Question 23

what is the function of substance P

Answer 23

causes intestinal contraction

Question 24

tachykinin genes are Gi, Gs or Gq and what is the mechanism for this

Answer 24

Gq
PLC -> IP3and DAG -> Calcium release

Question 25

true or false - substance P is involved in pain transmission

Answer 25

true

Question 26

review diagram on slide 5

Answer 26

i

Question 27

in terms of nociception, substance P is co released with what

Answer 27

glutamatergic sensory afferents

Question 28

what is another name for pain fibres

Answer 28

C fibres

Question 29

substance P is in what two types of clinical pain

Answer 29

neuropathic and fibrmyalgia

Question 30

in terms of Substance P, what reduces the response threshold for noxious stimuli

Answer 30

NK2 and NK3 agonists

Question 31

what is the active component of chili peppers

Answer 31

capsaicin

Question 32

capsaicin depletes ______

Answer 32

Substance P

Question 33

what is the final triggering step of the vomit reflex

Answer 33

substance P release in the CTZ

Question 34

what is Apripitant

Answer 34

NK1 substance P antagonist used as an anti emetic for chemo and post op nausea

Question 35

NK1 antagonists have what type of effects in animals

Answer 35

antidepressant effects

Question 36

what happens when NK1 is knocked out in mice and humans

Answer 36

shows decreased voluntary alcohol consumption in mice and cravings in trials of detoxified alcoholic inpatients

Question 37

NK2 antagonists have what effects in animals

Answer 37

anxiolytic and antidepressant effects

Question 38

NK3 antagonists have what effects in humans

Answer 38

antipsychotic effects

Question 39

what is the function of GI peptide hormones and its mechanism

Answer 39

triggers digestion of fat and protein -> triggers release of digestive enzymes from the pancreas and bile from gallbladder

Question 40

true or false - CCK peptides act as a hunger stimulant in response to rich foods

Answer 40

false - acts as a hunger suppressant

Question 41

CCK peptides are designated based on what

Answer 41

length in amino acids

Question 42

the CCK peptides are thought to act through which nerve

Answer 42

vagus nerve

Question 43

where are CCK receptors mainly expressed

Answer 43

CNS

Question 44

polymorphisms of CCK receptors are associated with what problems

Answer 44

panic disorder and schizophrenia

Question 45

IV administration of CCK4 leads to what

Answer 45

anxiety and panic attacks

Question 46

CCK receptor antagonists share structure and affinity with what class of drugs

Answer 46

benzodiazepines

Question 47

chronic benzodiazepine treatment does what to the responsiveness to CCK

Answer 47

decreases neural responsiveness to CCK

Question 48

during benzodiazepine withdrawal, where is the CCK density upregulated

Answer 48

hippocampus and frontal cortex

Question 49

proglumide is part of which CCK receptor family ? is it an agonist or antagonist? what is it used for

Answer 49

part of CCKa and CCKb antagonist -> used to treat stomach ulcers

Question 50

true or false - CCK receptor antagonists produce anxiolytic effects

Answer 50

true

Question 51

what is the nocebo effect

Answer 51

expectation of symptom worsening leads to negative outcomes

Question 52

what is verbally induced nocebo hyperalgesia and what does this result in

Answer 52

increased sensitivity to pain on expectancy -> decreased pain threshold is associated with increased activation of HPA axis -> cortisol release

Question 53

what kind of treatment reduced hyperalgesia and HPA activity

Answer 53

diazepam treatment

Question 54

true or false - proglumide, a CCK receptor antagonist, blocked both hyperalgesia and HPA activity

Answer 54

false - only hyperalgesia of verbally induced nocebo

Question 55

CART alone induced what? CART co adminstration with cocaine does what?

Answer 55

alone -> induces locomotor hyperactivity co admin -> inhibits motor hyperactivity

Question 56

CART expression is modified by what?

Answer 56

alcohol, nicotine and opiods

Question 57

CART is a exo/endogenous psychstimulant

Answer 57

endoCA

Question 58

true or false - CART is an anorexic peptide

Answer 58

true

Question 59

where is CART highly expressed

Answer 59

hypothalamus

Question 60

what is a treatment for binge eating and what does this do to CART expression

Answer 60

rimonabant -> increases CART expression

Question 61

CART signals what neurotransmitter in suppressing appetite

Answer 61

5HT

Question 62

true or false - CART stimulates the orexigenic pathways

Answer 62

false - inhibits it