1. Wake Up and Smell the Caffeine
Biology/Psychology 3506
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Caffeine

2. Introduction The most popular psychoactive drug in North America
How many people here DO NOT ingest caffeine?
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4. Introduction That includes: Coffee 130 mg Tea 40 mg
Soft Drinks (colas) 30 – 90 mg
Cold and Headache medications 15 – 50 mg
Red Bull 30 mg/100mg (about 150 mg in a large can)
Chocolate! 50 – 100 mg
Wake up pills 100 – 500 mg
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5. Introduction Almost always taken orally, absorbed in small intestine.
Crosses all barriers
Absorbed more slowly from cold beverages
Less than 2% is excreted
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6. Metabolism Half life is between 30 min and 3.5 hr
Metabolism slowed by birth control pills
Sped up by broccoli!
2x faster in smokers
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7. Metabolism That was with adults (well not kids anyway)
Different deal in kids and infants
85% excreted
4 DAY half life
Different pathways and metabolism than in adults
More similar to non-humans
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8. Neurophysiological Effects.
Like alcohol, we don’t know!
Might block adenosine
Neuromodulator that inhibits firing
So, caffeine disinhibits?
High doeses block benzodiazipine receptors
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9. Neurophysiological Effects
Might cause release of epinephrine
Causes smooth muscles to relax, striate muscles to contract
Decreases airway resistance
Good for asthma, colds
Constriction of blood vessels to the brain
Dilation other places
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10. Neuropshysiological Effects
Not sure if it helps performance
Does reduce drowsiness,boredom.
Increases FA levels, could be performance enhancing, especially for long athletic events.
Controlled substance.
Increases time in light sleep
Stages 1 and 2
Can counteract barbiturates.
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11. Effects on Nonhumans Small doses increase SMA
Large doses do the opposite
Increases FR responding
Affects timing
Increases suppressed behaviour.
Generalizes to coke, not to amphetamine.
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12. But, how does that first cup make you feel?
Humans are great at discriminating
1.8 mg, about a sip of coffee!!
Caffeine makes us:
Energized
Focused
Motivated
Same in non users
All at low-moderate doses ( mg)
About a cup of coffee.
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13. Could I ever use a coffee
Tolerance
Sustained use leads to more adenosine receptors
Whole deal changes if big dose given to non users.
Withdrawal
Headache
Flu like symptoms
Bad attitude in general
100 mg a day, most all of us!
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14. Reinforcing Properties
Hard to get animals to self-administer
Will prime cocaine use
Lots of variation in us
Task demands
Caffeine experience.
Demand is relatively inelastic.
Late 1970s, 6 bucks a pound.
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15. Bad Stuff Cancer? Caffeinism OD? Reproduction Cardiac effects?
30-80 cups of coffee
Reproduction
Chromosomal damage?
Toxicity
Cardiac effects?
Depends on method
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Caffeine

16. Beware the International Coffee Conspiracy!
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