Transcript College Students

Proseminar in
Biological
Psychology
Lecture 4
Marijuana
2/3 of Americans older than 12 drink alcohol
 1/4 of Adult Americans smoke
 100 gm of Caffeine/year
 1/3 of Americans older than 12 have used
illicit drugs at least once
Marijuana
Socially acceptable
National Surveys
College Students
YEAR
Marijuana
Cocaine
93
94
27.9
29.3
2.7
2.0
95
96
31.2 33.1
3.6
2.9
97
31.6
3.4
98
99
00
01
35.9 35.9 35.2 34.0
4.6
4.6
4.8
4.7
Source: University of Michigan,
Monitoring the Future National Survey Results on Drug Use, 1975-2003,
Volume II: College Students, 2004.
02
03
35.6
33.7 %
4.8
5.4 %
Percent of College Students/Young Adults Using Marijuana,
2003–2004
College
Students
2003
2004
Young Adults
2003
2004
19.3%
18.9%
17.3%
16.5%
Past
year
33.7
33.3
29.0
29.2
Lifetime
50.7
49.1
57.2
57.4
Past
month
National Institute on Drug Abuse and University of Michigan, Monitoring the Future National
Survey Results on Drug Use, 1975–2004, Volume II: College Students & Adults Ages 19–45, 2005
"We now know that marihuana –
•Destroys will power, making a jellyfish of
the user. He cannot say no.
•Eliminates the line between right and
wrong, and substitutes one's own warped
desires or the base suggestions of others
as the standard of right.
•Above all, causes crime; fills the victim
with an irrepressible urge to violence.
•Incites to revolting immoralities,
including rape and murder.
•Causes many accidents, but industrial
and automobile.
•Ruins careers forever.
•Causes insanity as its specialty.
•Either in self-defense or as a means of
revenue, users make smokers of others,
thus perpetuating the evil."
1930’s
Reefer Madness!!!!!
H. Anslinger (1930’s) FBN
•Brain damage
•Criminal behavior
•Insanity
•Sexual perversion
Marijuana (cannabis sativa)
• Dried leaves and flowers cannabis plant
• Contains over 400 different chemicals
• 60 are cannabis
Delta 9-Tetrahydrocannabinol (THC)
• 1 joint = 10 to 20 mg of THC
• Inhalation  Lungs Brain (BBB)
• Lipid soluable: weeks in system
2 Receptors (1988)
CB1
GPCR’s
CB2
• 1 joint = 10 to 20 mg of THC
• Inhalation  Lungs Brain (BBB)
• Lipid soluable: weeks in system
2 Receptors (1988)
CB1
GPCR’s
CB2
Brain regions in which cannabinoid receptors are abundant
Cerebellum
Body movement coordination
Hippocampus
Learning and memory
Cerebral cortex, especially
cingulate, frontal, and
parietal regions
Higher cognitive functions
Nucleus accumbens
Reward
Basal ganglia
Movement control
moderately concentrated
Hypothalamus
temp reg, salt, water balance,
reproductive function
Amygdala
Emotional response, fear
Spinal cord
Peripheral sensation, pain
Brain stem
Sleep, arousal, temp reg, motor
control
Central gray
Analgesia
Nucleus of the solitary tract
Visceral sensation, nausea
vomiting
Localization of THC Binding Sites
VTA, nucleus accumbens, caudate nucleus,
hippocampus, and cerebellum
THC affects two neurotransmitters:
Dopamine & GABA levels may also be altered
Dopamine
GABA
Dopamine
Dopamine Receptor
Why do we have these receptors?
Anandamide (1992): endogenous THC!
(just like "endorphin" is the brain's own morphine)
• binds to THC receptors
• is synthesized from lipid, a fat-like material
in the cell membranes – not made in terminal!!!
• Synthesized in the hippocampus, thalamus, cortex, striatum,
lowest in the cerebellum, pons and medulla
• Important signal early in development: embyro to uterus wall
Why would we have a chemical in the brain that
disrupts short-term memory??
Anandamide may be involved in eliminating unneeded information from memory
• Anandamide discovered in chocolate
• slows the destruction of chemicals that
activate marijuana's receptor in the brain
Use of Marijuana for Chemo Patients
Vomiting: 5 HT3 receptors
in raphe nucleus
Medicinal Purposes
Serotoninergic
THC binds 5 HT3  anti-emetic
(anti vomiting)
MARINOL® (dronabinol): synthetic
version of a naturally occurring delta-9THC: Anandamide Agonist
http://www.marinol.com/slides.html