Caffeine

Question 1

What kind of chemical is caffeine?

Answer 1

• in the group of methylxanthines

- which is in the group of alkaloid

Question 2

Where are alkaloids naturally found?

Answer 2

• in plants and the human body
• subcomponent of many organic compounds
• lipid soluble

Question 3

How is caffeine processed in the body?

Answer 3

• caffeine breaks down to theophylline and theobromine which breaks down to paraxanthine

Question 4

What are the active metabolites of caffeine?

Answer 4

• theophylline
• theobromine
• paraxanthine

Question 5

What are the metabolites of caffeine structurally similar to?

Answer 5

• serotonin
• histamine
• dopamine
• (glutamate)

Question 6

What is a neuromodulator?

Answer 6

• a chemical used by a neuron to communicate to other neurons about their function
• regulate gene expression and set points

Question 7

What is adenosine?

Answer 7

• a neuromodulator

Question 8

What effect does adenosine have?

Answer 8

• inhibitory effect
• sleep/arousal
• cognition and memory learning

Question 9

Where does adenosine act to influence sleep and arousal?

Answer 9

• striatum

- glutamate antagonist

Question 10

Where does adenosine act to influence cognition and memory/learning?

Answer 10

• hippocampus

- dopamine antagonist

Question 11

How does caffeine affect adenosine?

Answer 11

• adenosine antagonist for A1 receptors

Question 12

What function are the adenosine A1 receptors involved in?

Answer 12

• slowing metabolic function via a retrograde messenger and postsynaptic depression of NMDA receptor

Question 13

What functions are NMDA receptors involved in?

Answer 13

• memory, synaptic plasticity

- hebbian learning

Question 14

If caffeine is an adenosine antagonist, what does this effect/result in?

Answer 14

• caffeine inhibits adenosine receptors which results in facilitation of memory and synaptic plasticity

Question 15

What are the two negative effects of caffeine?

Answer 15

• hyperactivation results in inability to focus

- constriction of vasculature in the brain results in migraines

Question 16

What are both adenosine A1 and A2a receptors involved in?

Answer 16

• oxygen in blood flow

- reduced heart rate

Question 17

Why are caffeine and theophylline used to avoid hypoxia?

Answer 17

• because they are antagonists to A1 and A2a receptors which then stimulates respiration

Question 18

What are the three new points of research in regards to caffeine and adenosine?

Answer 18

• opens BBB: caffeine limits permeability
• A3 can inhibit melanoma cells: caffeine interferes
• A2a: anti-inflammatory agent: caffeine allows inflammation

Question 19

What are the general behavioural effects of caffeine?

Answer 19

• mood elevation

- performance enhancement

Question 20

What explains the mood elevation effects of caffeine?

Answer 20

• “placebo”: dopaminergic release

- emotional attribution: James-Lange theory

Question 21

What explains the performance enhancement effects of caffeine?

Answer 21

• enhances boring or simple tasks (not complex tasks)
• impairs decision making in physical tasks
• decreases fatigue

Question 22

What is a common misconception of the effects of caffeine?

Answer 22

• it is not sobering like many people believe

- alertness is misattributed

Question 23

Absorption and elimination of caffeine are?

Answer 23

• highly variable

Question 24

Why is caffeine dose-dependent?

Answer 24

• developmental stage (children need more)

- time to peak does not change across doses (gate/binding mechanism)

Question 25

How is caffeine affected in the presence of sugars?

Answer 25

• concentration levels/time decreases

Question 26

How does experience affect caffeine?

Answer 26

• more experience results in longer times

Question 27

Does caffeine have observable tolerance and withdrawal?

Answer 27

• can observe physiological effects but not the psychological effects
• research does not find consistent patterns of withdrawal

Question 28

What is the problem with studying tolerance and withdrawal from caffeine?

Answer 28

• variability of absorption
• poor operationalization of dosage
• individual differences
• small rates

Question 29

What are the three conditions that qualify a “caffeine use disorder” by the DSM-V?

Answer 29

• tolerance
• withdrawal
• desire to quit/control use but continuing to use

Question 30

Is caffeine safe by the FDA standards?

Answer 30

• “generally regarded as safe”

- 10 grams would be toxic (57 cups of coffee)

Question 31

What are energy drinks a combination of?

Answer 31

• xanthine

- potentiators

Question 32

What are the problems with energy drinks?

Answer 32

• advertised as low caffeine
• comparable potencies unknown
• timing (excitotoxicity and kindling)

Question 33

How can energy drinks be advertised as low caffeine?

Answer 33

• highly variable xanthine content
• caffeine listed if added but not if naturally occurring
• metabolites, precursors and compounds not measured

Question 34

What is an example of a naturally occurring potentiator and xanthines?

Answer 34

• potentiator: panax ginseng root

- xanthines: guarana seed

Question 35

What is taurine?

Answer 35

• similar to GABA

- neuroprotectant

Question 36

What is GABA?

Answer 36

• inhibitory in adults
• excitatory in children
• anxiolytic effects
• antero/retrograde amnesia

Question 37

What is the problem with consuming taurine?

Answer 37

• it is similar to GABA
• exitotoxicity and developmental effects
• boycotts natural warning mechanism by anxiolytic effects
• boycotts learning mechanism

Question 38

What is a neuroprotectant?

Answer 38

• inhibits glutamate-induced excitotoxicty
• trophic and inhibitory modulator
• altered in neuropsychiatric disorders
• antioxidant/prevent oxidative stress

Question 39

What are the effects of caffeine and taurine together?

Answer 39

• synergistic effects (caffeine potentiated)
• accuracy decreased and reaction time increased
• “aerobic” heart pattern (potential stress)
• potential increase in mood (feel less ill/negative)