Neurotransmitters and Functions

Acetylcholine (ACh):

Enables muscle action, learning, and memory

Dopamine

Influences movement, learning, attention, and emotion

Serotonin:

Affects mood, hunger, sleep, and arousal

Norepinephrine:

Helps control alertness and arousal

GABA:

Major inhibitory neurotransmitter

Glutamate

major exibitory nuertransmitter

Endorphins:

Natural opioids that reduce pain and boost mood

Agonist:

Molecule that increases neurotransmitter's action (mimics or enhances)

Antagonist:

Molecule that inhibits or blocks neurotransmitter's action

Reuptake Inhibitors:

Block reuptake, increasing neurotransmitter availability

Depressants:

Reduce neural activity and slow body functions

Alcohol: Disinhibits behavior, impairs judgment and coordination

Disinhibits behavior, impairs judgment and coordination

Barbiturates:

Depress CNS activity, reduce anxiety but impair memory

Opioids:

Depress neural activity, temporarily lessen pain and anxiety

Stimulants:

Excite neural activity and speed up body functions

Caffeine:

Blocks adenosine receptors, increases alertness

Nicotine:

Stimulates ACh receptors, then depresses them

Amphetamines:

Increase dopamine and norepinephrine activity

Cocaine:

Blocks dopamine reuptake

Hallucinogens:

Distort perceptions and evoke sensory images

LSD:

Affects serotonin system

Marijuana:

Affects cannabinoid receptors

Tolerance:

Diminishing effect with regular use; need larger doses

Physical Dependence:

Body adapts to drug; withdrawal symptoms occur without it

Psychological Dependence:

Mental craving for drug's effects

Withdrawal:

Discomfort and distress following discontinued use