Psychopharmacology

1
Nicotine and Caffeine Chapter 12
2
Leaves of the Nicotiana tabacum plant
Nicotine
History
3
Nicotine
Routes of Administration Inhalation Chewing Snor
ting Transdermal
4
Nicotine

• Metabolism of Nicotine
• liver converts nicotine into metabolites
• cotinine
• half life 2 hrs
• acute tolerance

5
Nicotine

• Site of action for nicotine
• Nicotinic cholinergic receptors (nAChR)
• Basic functions of different receptors
• Open Na channels ? increase firing potential
• Allows Ca2 into cell ? 2nd messengers
• Enhances NT release (presynaptic)

6
Nicotine

• Site of action for nicotine
• Nicotinic cholinergic receptors (nAChR)
• Locations of receptors
• Neuromuscular junction at muscles
• Low doses
• High doses depolarization block
• PNS
• CNS
• Postsynaptic
• Presynaptic membranes of other NT neurons

7
Changes in cognitive functionNicotine-induced
reduction of reaction time in a rapid visual
information processing task
Nicotine
8
Nicotine
Activation of mesolimbic dopamine system
Time
9
Nicotine
Activation of mesolimbic dopamine systemNicotine
self-administration in rats first exposed to the
drug during adolescence vs. adulthood
10
Nicotine

• Changes in mood
• Smokers
• Non-smokers

11
Nicotine
Factors other than NicotineWhole-body PET scans
illustrating reduced MAO-B activity
12
Nicotine

• Tolerance
• - acute
• - chronic
• Withdrawal symptoms
• Decrease heart rate and blood pressure
• Irritability
• Hunger
• Sleep disturbances
• GI complaints
• Headache
• Impairment of concentration

13
Nicotine

• Effects of smoking on general health
• Increased risk for
• Cancer
• Cardiovascular disease
• Emphysema
• Chronic bronchitis
• Decreased birth weight in infants for mothers who
  smoked

14
Nicotine

• Why do people smoke?
• Nicotine resource model
• Deprivation reversal model
• Positive reinforcement (DA reward system)
• Substances other than nicotine
• Genetic factors?

15
Nicotine
Treatment of nicotine dependence