Wake Up and Smell the Caffeine

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Wake Up and Smell the Caffeine

• Psychology 2800

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Introduction

• The most popular psychoactive drug in North
  America
• How many people here DO NOT ingest caffeine?

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(No Transcript)
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Introduction

• That includes
• Coffee 130 mg
• Tea 40 mg
• Soft Drinks (colas) 30 90 mg
• Cold and Headache medications 15 50 mg
• Rev ?, probably about 100 mg
• Chocolate! 50 100 mg
• Wake up pills 100 500 mg

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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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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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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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Neurophysiological Effects.

• Like alcohol, we dont know!
• Might block adenosine
• Neuromodulator that inhibits firing
• So, caffeine disinhibits?
• High doeses block benzodiazipine receptors

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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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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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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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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 (20-200 mg)
• About a cup of coffee.

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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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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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Bad Stuff

• Cancer?
• Caffeinism
• OD?
• 30-80 cups of coffee
• Reproduction
• Chromosomal damage?
• Toxicity
• Cardiac effects?
• Depends on method

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Beware the International Coffee Conspiracy!