Recreational Drugs

dopamine

acts as a natural reward chemical, behaviours which lead to positive reinforcement are associated with increased activity in the (—-) reward system

nucleus accumbens

an area of the brain associated with the brain’s reward system

ventral tegmental area

an area of the midbrain associated with the brain’s reward system and origin of dopaminergic activity

mode of action

gaba

most important inhibitory neurotransmitter, makes it more difficult for messages between synapses to be transmitted, alcohol increases the amount of it in the prefrontal cortex

endorphines

the body’s natural opiates (pain controlling). Inhibitory. Prevent neural messages from being transmitted

serotonin

closely linked to mood and emotions. clinical depression linked to reduced levels of serotonin

adrenaline and noradrenalin

found in the bloodstream and act as hormones regulating the fight or flight response.

in the brain the act as neurotransmitters, booting attention and ability to focus as well as mood

up regulation

increase in number of receptor sites sensitive to neurotransmitters with opposing effects, such as gaba, which inhibits the release of dopamine, drug user has to take more to get same effect

down regulation

where the brain reduces its own natural production and response to dopamine. more drug is needed for users to feel the same effect

Olds and Milner

discovered rats and monkeys would press a lever that stimulated dopamine release in their brains.

monkeys pressed 2000 times in an hour

rats pressed 8000 times in an hour

often continued for hours until they collapsed from exhaustion

Alexander

luxury rat park, rats in a boring cage became addicted to a dopamine pedal, rats in a luxury park with lots of comfort, food and entertainment hardly used the dopamine pedal