Neurotransmitters, Hormones, and Psychoactive Drugs

Acetylcholine

Muscle action, learning, memory

Substance P

Transmits sensory signals from nerves to CNS

Dopamine

Movement, learning, attention, emotions; low levels can lead to depression, high levels can lead to schizophrenia; receptors are blocked by antipsychotic drugs

Serotonin

Hunger, sleep, arousal, mood; levels boosted by antidepressants

Endorphins

Pain control and tolerance, pleasure

GABA

Sleep, movement, slows down nervous system (helps with anxiety)

Epinephrine (adrenaline)

Forms memories, bodily response to highly emotional situations

Glutamate

Long term memory, learning

Norepinephrine

“Fight or flight” response, increases blood pressure & heart rate & alertness

Leptin

Regulates energy by inhibiting hunger (tells brain you are full)

Ghrelin

Signals hunger and releases growth hormones

Melatonin

Produced by pineal gland; regulates sleep cycle

Oxytocin

Released by pituitary gland; promotes affection and emotional bonding

Stimulants

Excite and promote neural activity, provide energy, reduce appetite, make irritable; caffeine, nicotine, cocaine

Depressants

Reduce neural activity, drowsiness, muscle relaxation, lowered breathing; alcohol, sleeping pills

Hallucinogens

Senses things that are not there, reduces motivation and can lead to panic; LSD, marijuana, peyote

Opioids

Function as a depressant, but are addictive; morphine, oxycodon, heroin