Download Drugs and the Nervous System

Drugs and the Nervous
System
Classes of Drugs
1. Depressants
2. Stimulants
3. Hallucinogens
Depressants
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slow down the CNS;
relaxes and causes people to feel less pain.
Also decreases coordination and movement
ex. Alcohol, heroin, morphine, Valium, anesthetics
anesthetics can be general or local
local: affect only a small area
general: affect all nervous system activity
Depressant Physiology
• Valium increases GABA levels to reduce
anxiety
• By binding to the GABAA receptor,
barbiturates (and ethanol) increase the
natural inhibitory effect of GABA synapses.
Stimulants
• speed up the CNS;
• increase energy and confidence
• ex. Caffeine, cocaine, MDMD (ecstasy) and nicotine
Stimulant Physiology
• Nicotine binds to a subset of acetylcholine (ACh) receptors.
• Ecstasy depletes serotonin supply, and long term use may permanently alter
neurotransmitter levels in the CNS
Hallucinogens
• cause an altered state or reality; affect
memory or pleasure centers as well as
perception
• Marijuana, LSD (acid)
Hallucinogens
Physiology
• Marijuana binds to serotonin receptors
Interesting Web sites
• http://users.rcn.com/jkimball.ma.ultranet/Bi
ologyPages/D/Drugs.html