Nicotine Flashcards
Nicotine Acts as an
agonist at the nicotinic
acetylcholine receptor (NAChR)
Nicotine Acute toxicity marked by
nausea,
vomiting, faintness, profuse
sweating, hypothermia, decrease
blood pressure, unconsciousness
Administration
oral (chewing tobacco), inhalation
(cigarettes, cigars, and pipes), intranasal
(insufflation – snuff), transdermal (patch)
Nicotine reaches the brain from the lungs
~ 7
seconds after inhalation
Much faster than intravenous injection
nicotine is metabolized
Metabolized in the liver to various metabolites
nicotine Rate of liver metabolism proportional to the
addictive potential in humans
Faster metabolism →
more addictive
High affinity NAChR found in (8)
cortex,
thalamus,
striatum,
hippocampus,
substantia nigra,
ventral tegmental area,
locus coeruleus,
raphe nuclei
Peripheral receptors are found in the
autonomic ganglia (sympathetic and
parasympathetic)
Reinforcement of nicotine
Cholinergic inputs to the VTA are responsible for activating mesolimbic dopamine neurons.
Nicotine activates NAChR on the
mesolimbic dopamine projections from the VTA to the nucleus accumbens to moderate nicotine’s reinforcing effects.
Nicotine is a psychostimulant…
sometimes
Nicotine is a psychostimulant… sometimes (current smokers)
increased calmness and relaxation
increases performance on cognitive tasks
Increases attention
Enhances mood
Nicotine is a psychostimulant… sometimes (non-smokers)
anxiety,
heightened tension,
lightheadedness,
dizziness
nausea
Nicotine in high doses decreases reaction time
Nicotine decreases
reaction time in a
trial requiring sustained visual attention.
Reaction time tests Current smokers had a
greater
sensitivity to nicotine than did nonsmokers s (lower doses of nicotine effective
at reducing reaction time)
Reaction time tests Abstinent smokers had a
longer
reaction time than non-smokers
reaction time findings
the stimulant effects of nicotine
may at best compensate for a deficit.