Nicotine (Final Exam)

Question 1

What is the psychoactive ingredient in tobacco (natural source)?

Answer 1

Nicotine

Question 2

Why were cigarettes the dominate form of tobacco consumption in the 20th century?

Answer 2

It was due to new curing methods and invention of cigarette machine

Question 3

What percentage of US adults use some tobacco product?

Answer 3

About 20%

Question 4

What are the three routes of nicotine administration?

Answer 4

Smoking/Vaping, By mouth, By nose

Question 5

What is the quickest way to get nicotine into your system? Why?

Answer 5

Smoking because it is absorbed via the lungs

Question 6

What are the names of the methods for oral administration of nicotine?

Answer 6

chew, dip, snus

Question 7

What is the name of the method for nasal administration of nicotine?

Answer 7

snuff

Question 8

True or False: E-cigarettes are safer than cigarettes

Answer 8

False! There are harmful additives in the E-cigarette cartirages

Question 9

Smoking/Vaping causes nicotine to hit brain very fast. How quickly does nicotine get to the brain?

Answer 9

7 seconds

Question 10

Which is a faster route of administration: smoking or IV?

Answer 10

Smoking

Question 11

Nicotine is mostly metabolized into ______ by a cytochrome P450 enzyme

Answer 11

Cotinine

Question 12

Individual variation in the expression of this cytochrome P450 enzyme (metabolizes nicotine):

Answer 12

• Half-life of nicotine averages at 2 hours, but varies among individuals
  -People with reduced nicotine metabolism are less likely to become smokers

Question 13

nicotine is a (agonist or antagonist) at nicotinic acetylcholine receptors (nAChRs)

Answer 13

agonist

Question 14

nicotine is an agonist at nicotinic acetylcholine receptors (nAChRs), which are ionotropic receptors found in the…?

Answer 14

-Brain and spinal cord
-autonomic nervous system
- neuromuscular junction

Question 15

Acetylcholine is implicated in cortical function related to what 2 things? (ref. nicotine effects on cognition)

Answer 15

sustained attention and memory

Question 16

True or False: Nicotine can enhance performance of attention demanding tasks

Answer 16

True

Question 17

What type of animal showed enhanced performance on cognitive tasks with nicotine?

Answer 17

Rat

Question 18

What does smoking do for mood according to smokers?

Answer 18

relaxes them, alleviates stress, and helps concentration

Question 19

The mood effects reported by smokers are hypothesized to be partially associated with relief from what?

Answer 19

Withdrawal

Question 20

What causes a high dose of nicotine to produce unpleasant symtpoms?

Answer 20

Largely due to autonomic actions of nicotine, but strong tolerance to these actions

Question 21

Lethal doses of nicotine are rare, but what is the mechanism of death of nicotine?

Answer 21

It kills through depolarization block of muscles involved in respiration (similar to nerve gas)

Question 22

Are withdrawal symptoms of nicotine the same or opposite to acute drug effects?

Answer 22

Opposite

Question 23

What do regular smokers feel when they don’t smoke?

Answer 23

irritability, stress, and difficulty concentrating

Question 24

What is acute tolerance of nicotine due to?

Answer 24

Desensitization of nicotinic receptors (nAChR)

Question 25

Chronic tolerance lasts a long or short time after smoking cessation?

Answer 25

a long time

Question 26

Pharmacodynamic tolerance of nicotine:

Answer 26

nAChRs have decreased funciton

Question 27

Harmful effects of chronic use of nicotine:

Answer 27

- premature death -increased risk for lung disease, cardiovascular diseases, and cognitive deficits

Question 28

What is the precursor of Acetylcholine?

Answer 28

Choline (vitamin found in many foods)

Question 29

What enzyme synthesizes Acetylcholine?

Answer 29

Choline acetyl-transferase (ChAT)

Question 30

What happens during the degredation of ACh?

Answer 30

acetylcholinesterase (AChE) metabolizes ACh into choline and acetic acid

Question 31

What is the vesicular transporter of ACh called?

Answer 31

vesicular acetylcholine transporter (VAChT)

Question 32

How is ACh inactivated?

Answer 32

First by Metabolism and THEN Uptake

Question 33

Inactivation of ACh process:

Answer 33

ACh undergoes rapid degradation/metabolism by AChE, converting it back to choline. Then, choline is then taken up by the choline transporter and is used to make more ACh

Question 34

Types of receptors for ACh:

Answer 34

Muscarinic and Nicotinic

Question 35

Are muscarinic ACh receptors (mAChRs) ionotropic or metabotropic?

Answer 35

Metabotropic (GPCRs)

Question 36

Are nicotinic ACh receptors (nAChRs) ionotropic or metabotropic?

Answer 36

ionotropic (ion channels)

Question 37

What makes up a Nicotinic ACh receptor?

Answer 37

It is a pentameric ligand-gated cation channel, so 5 subunits

Question 38

Brain nAChRs:

Answer 38

-consist of 2 alpha subunits and 3 beta subunits OR just 5 alpha subunits -binds to nicotine with higher affinity

Question 39

Muscle nAChRs:

Answer 39

have 2 ACh binding sites

Question 40

What type of cation channels do nicotinic ACh receptors have?

Answer 40

mostly Na+ in the periphery; NA+ and Ca2+ in the brain

Question 41

Effect of nicotinic ACh receptors presynaptically and postsynaptically

Answer 41

Postsynaptically: rapid depolarization (EPSPs) that increase neuronal firing or contract muscle Presynaptically: enhance release of neurotransmitters

Question 42

Desensitization of nicotinic ACh receptors

Answer 42

nAChRs desensitize with continuous exposure to agonist (the channel closes); this is reversible. Causes acute tolerance to nicotine

Question 43

Is nicotine self-administered by animals?

Answer 43

yes

Question 44

Nicotine (increases /decreases) firing activity of DA cells in VTA. Does this cause more or less DA release at terminals in the nucleus accumbens?

Answer 44

increases; more

Question 45

What are the nAChr subtypes?

Answer 45

alpha4Beta2 and alpha7

Question 46

what are the different effects of the nAChR subtypes alpha4Beta2 and alpha7?

Answer 46

alpha4Beta2: contains receptors involved in rewarding effects of nicotine alpha7: contains receptors involved in cognitive (attention) effects of nicotine

Question 47

What route of administration leads to occupancy of alpha4Beta2 nAChRs?

Answer 47

smoking

Question 48

The knockout of which nAChR subunit does not impair the desire to self-administer nicotine intravenously?

Answer 48

the knockout of alpha7 (alpha4, alpha6, and Beta2 all impaired self administration)

Question 49

alpha7-containing receptors are important for nicotine effects on ________.

Answer 49

attention

Question 50

Menthol effects on nicotine:

Answer 50

- menthol intensified nicotine withdrawal symptoms -menthol increased alpha4Beta2 nAChRs (even without nicotine)

Question 51

What two factors contribute to nicotine addiciton?

Answer 51

Psychological (cue-induced craving) and pharmacological (dependence)

Question 52

NRT helps treat dependence and withdrawal. What does NRT stand for?

Answer 52

Nicotine Replacement Therapy

Question 53

What treatment options target withdrawal AND craving?

Answer 53

-Buproprion (weak nAChR antagonist) - Varenicline (partial agonist at alpha4/Beta2 receptors & is the most effective treatment)